Computational materials design and its application to spintronics

Size: px
Start display at page:

Download "Computational materials design and its application to spintronics"

Transcription

1 Papan-Germany Joint Workshop 2009 Kyoto, Jan Computational materials design and its application to spintronics H. Akai, M. Ogura, and N.H. Long Department of Physics, Osaka University

2 What is CMD? CMD : computational materials design To create/synthesize materials in computers Based on first principles electronic structure calculation, i.e., quantum simulation Traditional materials design 21st century's alchemist CMD

3 Simulation and design Design: the inverse problem of simulation Quantum Simulation Materials & Structure predict predict Properties & Functionalitie s Quantum Design

4 How to solve the inverse problem? CMD Engine Verify Functionality Predict New Materials Quantum Simulation Find Mechanisms Analyze Physical Mechanism Experimental Verification Integrate Mechanisms

5 Submicron physics Simulation/design of whole submicron structures fm pm nm Most important but difficult scale range submicron μm mm Quantal Yet large scale Real devices

6 An example Transport properties of real device structures Parallel coupling Antiparallel coupling MnPt Ru CoFe Cu CoFe NiFe Ta CoFe 25nm

7 Our approach First-principles LDA calculation of transport properties of metals, semiconductors, alloys, layered systems and hetero structures. KKR Green s function method combined with Kubo- Greenwood formula and CPA.

8 1. Halfmetallic AF (compensated ferrimagnets) When two magnetic ions exist One ion more than half d, the other less than half Ferromagnetic coupling V d 3 DOS energy metallic J H E F Co J H d 7 Superexchange works (no degeneracy)

9 Mechanisms In the case of anti-parallel coupling Antiferromagnetic coupling V d 3 half-metallic E F Co d 7 2J H Double exchange works (degeneracy)

10 (ZnCrFe)S (Zn 0.9 Cr 0.05 Fe 0.05 )S AP DOS (states/ry) Antiferro Up spin Down spin total (left) 80 Cr 3d (right) Fe 3d (right) VB half metallic CB P DOS (states/ry) Ferro VB metallic CB D DOS (states/ry) Spin glass Energy relative to Fermi energy (Ry) VB metallic CB

11 Transport properties ferro antiferro Anti-phase domain boundary

12 Transport properties of HM AF DMS? Anti-phase domain boundary

13 (Zn,Cr,Fe)S films Parallel coupling Anti-parallel coupling

14 DC conductivity of (Zn,Cr,Fe)S 1.36x10-3 Ωcm 6.79x10-3 Ωcm Parallel coupling Anti-parallel coupling H. Akai and M.O. J Phys. D 40 (2007) 1238

15 New type of HM AF: (AB)X 2 A and B are transition metals, X is chalcogens or pnictogens, Choose A and B such that total valence d electrons number is 10: one being less than half-filled, another being more than half-filled: ex. (FeCr)Se 2, Structures: NiAs-, Zinc-blende-, chalcopyrite-, wurtzite-, NaCl-type. NiAs-type wurtzite-type ZB-type NaCl-type Chalcopyrite-type

16 NiAs-type (FeCr)Se 2 DOS (states/ry) total Cr d Fe d VB CB AF half metallic total Cr d Fe d DOS (states/ry) 40 0 F metallic total Cr d Fe d DOS (states/ry) metallic SG Energy relative to Fermi energy (Ry)

17 Robust half-metallicity total Cr d Fe d antiferromagnetic disordered state (A 0.5 B 0.5 )X DOS (states/ry) NiAs-type (Fe 0.5 Cr 0.5 )Se Energy relative to Fermi energy (Ry) more than two components (AB 0.5 C 0.5 )X 2 DOS (states/ry) total Cr d Co 0.5 d Mn 0.5 d NiAs-type (CrCo 0.5 Mn 0.5 )Se Energy relative to Fermi energy (Ry)

18 Magnetic moments and total energy Total energy: E AF E LMD = mry E F E LMD = 2.76 mry E ordered E disordered = mry E formation = E CrSe + E FeSe 2E (FeCr)Se2 = 33.5 mry Magnetic moments: Materials Local magnetic moment (μb) Total (μb) (FeCr)Se 2 Cr Fe Se Ordered state Disordered state Stable in antiferromagnetic ordered state

19 Many cases exhibit HM AF Crystal structure NiAs-type structure Zinc-blende structure Wurtzite structure Chalcopyrite structure NaCl-type structure Materials 1E AF - E LMD 2E FR - E LMD (mry) E order - E disorder (mry) Formation E A +E B -2E AB (mry) MF T N (K) (FeCr)Se (VCo)Se (FeCr)Te (VCo)S (FeCr)Se (FeCr)Te (FeCr)Po (FeCr)Te (FeCr)Se (VCo)S non (FeCr)Se non (FeCr)S (VCo)S Transition metal chalcogenides CA

20 (AB)N 2 Crystal structure NiAs-type structure Zinc-blende structure Wurtzite structure Chalcopyrite structure NaCl-type structure Materials 1E AF - E LMD 2E FR - E LMD (mry) E order - E disorder (mry) Formation E A +E B -2E AB (mry) MF T N (K) (MnCo)N (MnCo)N (MnCo)N (MnCo)N non (MnCo)N CA

21 Applications to GMR and TMR devices ال Bit line Bit line Pinned-layer Magnetic free layer Nonmagnetic layer Inner-layer Ru Outer-layer Antiferromagnetic layer Write word line Magnetic free layer Nonmagnetic layer Half-metallic antiferromagnets Write word line Structure using HM AF Currently used structure

22 GMR ratio of GMR/TMR devices currently used structure GMR ratio 19% 1.85Å resistivity µωcm Fe 0.85 Co 0.15 resistivity µωcm 3.70Å Cu 1.85Å 1.85Å 1.85Å Fe 0.85 Co 0.15 Ru Fe 0.85 Co Å Mn

23 Our design of new MRAM cell resistivity µωcm GMR ratio 720% resistivity µωcm 5.77Å Fe 2 Se Å Cu 2 Se Å ZB (FeCr)Se 2

24 Magnetic metallic layers: bcc-cu and bcc-fe GMR ratio 54% resistivity µωcm resistivity µωcm 4.33Å Fe 7.21Å Cu 5.77Å ZB (FeCr)Se 2 Cu Fe Cr

25 Half-metallic diluted antiferromagnetic semiconductors resistivity 2.25 µωcm GMR ratio 264% resistivity 8.18 µωcm 5.67Å GaMnAs 5.67Å GaAlAs 5.67Å ZB Zn(CrFe)Se

26 TMR devices: nonmagnetic spacer resistivity 473 µωcm TMR ratio 3300% resistivity µωcm 5.37Å Cr 2 S Å Ca 2 S Å NiAs (FeCr)S 2

27 2. Spin transport Transport properties and spin dynamics are of vital interest GMR spin injection / accumulation current induced magnetization reversal spin relaxation spin-pumping / battery Spin-Hall effect F/N/F cpp GMR structure F N F

28 What is spin transport? Electric motive force charge/spin current Spin motive force spin/charge current Aims: First principles calculation of DC conductivity Spin conductivity Spin Hall conductivity Inverse spin Hall conductivity Spin injection Spin accumulation

29 Charge and spin currents Current operators J c = e v J s = (h /2)σv Charge current vector Spin current tensor Correlation functions J c J c, J c J s, J s J c, J s J s where O 1 O 2 RR = Tr O 1 G R (E F )O 2 G R (E F ) O 1 O 2 RA = Tr O 1 G R (E F )O 2 G A (E F )

30 Conductivities e.g. σ zz cc = 1 2 R ( j c j c RR z c c RA ) z jz j z cs σ z,zz ( RR c jz j s RA ) zz = 1 2 R j c s z j zz sc σ zz,z = 1 2 R j s zz ( c RR j z s c RA ) jzz j z ss σ zz,zz ( RR s jzz j s RA ) zz = 1 2 R j s s zz j zz

31 Spin-orbit coupling Spin-diagonal components scalar relativistic + l z σ z Spin-off-diagonal components Δt Lσ,L 'σ ' ; r 2 dr R ( Lσ l x σ x + l y σ y )R L 'σ '

32 Summary First-principles calculation of charge and spin transport properties Half-metallic AF and new type of GMR Spin conductivity of alloy systems Co/CoCu/Cu hetero structure Quantitative discussion of spin injection/accumulation and relaxation

introduction: what is spin-electronics?

introduction: what is spin-electronics? Spin-dependent transport in layered magnetic metals Patrick Bruno Max-Planck-Institut für Mikrostrukturphysik, Halle, Germany Summary: introduction: what is spin-electronics giant magnetoresistance (GMR)

More information

Mon., Feb. 04 & Wed., Feb. 06, A few more instructive slides related to GMR and GMR sensors

Mon., Feb. 04 & Wed., Feb. 06, A few more instructive slides related to GMR and GMR sensors Mon., Feb. 04 & Wed., Feb. 06, 2013 A few more instructive slides related to GMR and GMR sensors Oscillating sign of Interlayer Exchange Coupling between two FM films separated by Ruthenium spacers of

More information

CHAPTER 2 MAGNETISM. 2.1 Magnetic materials

CHAPTER 2 MAGNETISM. 2.1 Magnetic materials CHAPTER 2 MAGNETISM Magnetism plays a crucial role in the development of memories for mass storage, and in sensors to name a few. Spintronics is an integration of the magnetic material with semiconductor

More information

CHAPTER 6. ELECTRONIC AND MAGNETIC STRUCTURE OF ZINC-BLENDE TYPE CaX (X = P, As and Sb) COMPOUNDS

CHAPTER 6. ELECTRONIC AND MAGNETIC STRUCTURE OF ZINC-BLENDE TYPE CaX (X = P, As and Sb) COMPOUNDS 143 CHAPTER 6 ELECTRONIC AND MAGNETIC STRUCTURE OF ZINC-BLENDE TYPE CaX (X = P, As and Sb) COMPOUNDS 6.1 INTRODUCTION Almost the complete search for possible magnetic materials has been performed utilizing

More information

Transition Elements. pranjoto utomo

Transition Elements. pranjoto utomo Transition Elements pranjoto utomo Definition What is transition metal? One of which forms one or more stable ions which have incompletely filled d orbitals. 30Zn? Definition Zink is not transition elements

More information

Pressure dependence of Curie temperature and resistivity of complex Heusler alloys

Pressure dependence of Curie temperature and resistivity of complex Heusler alloys DPG Frühjahrstagung Berlin, 25. - 30. März 2012 Sektion Kondensierte Materie (SKM), 2012 p. 1 Pressure dependence of Curie temperature and resistivity of complex Heusler alloys Václav Drchal Institute

More information

J 12 J 23 J 34. Driving forces in the nano-magnetism world. Intra-atomic exchange, electron correlation effects: Inter-atomic exchange: MAGNETIC ORDER

J 12 J 23 J 34. Driving forces in the nano-magnetism world. Intra-atomic exchange, electron correlation effects: Inter-atomic exchange: MAGNETIC ORDER Driving forces in the nano-magnetism world Intra-atomic exchange, electron correlation effects: LOCAL (ATOMIC) MAGNETIC MOMENTS m d or f electrons Inter-atomic exchange: MAGNETIC ORDER H exc J S S i j

More information

P. Khatua IIT Kanpur. D. Temple MCNC, Electronic Technologies. A. K. Majumdar, S. N. Bose National Centre for Basic Sciences, Kolkata

P. Khatua IIT Kanpur. D. Temple MCNC, Electronic Technologies. A. K. Majumdar, S. N. Bose National Centre for Basic Sciences, Kolkata The scaling law and its universality in the anomalous Hall effect of giant magnetoresistive Fe/Cr multilayers A. K. Majumdar S. N. Bose National Centre for Basic Sciences, Kolkata & Department of Physics

More information

EFFECTIVE MAGNETIC HAMILTONIANS: ab initio determination

EFFECTIVE MAGNETIC HAMILTONIANS: ab initio determination ICSM212, Istanbul, May 3, 212, Theoretical Magnetism I, 17:2 p. 1 EFFECTIVE MAGNETIC HAMILTONIANS: ab initio determination Václav Drchal Institute of Physics ASCR, Praha, Czech Republic in collaboration

More information

WORLD JOURNAL OF ENGINEERING

WORLD JOURNAL OF ENGINEERING Magnetism and half-metallicity of some Cr-based alloys and their potential for application in spintronic devices by Yong Liu, S. K. Bose and J. Kudrnovsk y reprinted from WORLD JOURNAL OF ENGINEERING VOLUME

More information

Magnetism (FM, AFM, FSM)

Magnetism (FM, AFM, FSM) Magnetism (FM, AFM, FSM) Karlheinz Schwarz Institute of Materials Chemistry TU Wien Localized vs. itinerant systems In localized systems (e.g. some rare earth) the magnetism is mainly governed by the atom

More information

Giant Magnetoresistance

Giant Magnetoresistance Giant Magnetoresistance This is a phenomenon that produces a large change in the resistance of certain materials as a magnetic field is applied. It is described as Giant because the observed effect is

More information

Italian School of Magnetism

Italian School of Magnetism Spintronics I 1. Introduction 3. Mott paradigm: two currents model 4. Giant MagnetoResistance: story and basic principles 5. Semiclassical model for CIP GMR Italian School of Magnetism Prof. Riccardo Bertacco

More information

MAGNETORESISTANCE PHENOMENA IN MAGNETIC MATERIALS AND DEVICES. J. M. De Teresa

MAGNETORESISTANCE PHENOMENA IN MAGNETIC MATERIALS AND DEVICES. J. M. De Teresa MAGNETORESISTANCE PHENOMENA IN MAGNETIC MATERIALS AND DEVICES J. M. De Teresa Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, Facultad de Ciencias, 50009 Zaragoza, Spain. E-mail:

More information

Enhanced spin orbit torques by oxygen incorporation in tungsten films

Enhanced spin orbit torques by oxygen incorporation in tungsten films Enhanced spin orbit torques by oxygen incorporation in tungsten films Timothy Phung IBM Almaden Research Center, San Jose, California, USA 1 Motivation: Memory devices based on spin currents Spin Transfer

More information

Spin electronics at the nanoscale. Michel Viret Service de Physique de l Etat Condensé CEA Saclay France

Spin electronics at the nanoscale. Michel Viret Service de Physique de l Etat Condensé CEA Saclay France Spin electronics at the nanoscale Michel Viret Service de Physique de l Etat Condensé CEA Saclay France Principles of spin electronics: ferromagnetic metals spin accumulation Resistivity of homogeneous

More information

ORBITAL DIAGRAM - A graphical representation of the quantum number "map" of electrons around an atom.

ORBITAL DIAGRAM - A graphical representation of the quantum number map of electrons around an atom. 178 (MAGNETIC) SPIN QUANTUM NUMBER: "spin down" or "spin up" - An ORBITAL (region with fixed "n", "l" and "ml" values) can hold TWO electrons. ORBITAL DIAGRAM - A graphical representation of the quantum

More information

Advanced Lab Course. Tunneling Magneto Resistance

Advanced Lab Course. Tunneling Magneto Resistance Advanced Lab Course Tunneling Magneto Resistance M06 As of: 015-04-01 Aim: Measurement of tunneling magnetoresistance for different sample sizes and recording the TMR in dependency on the voltage. Content

More information

Magnetism. Ram Seshadri MRL 2031, x6129, Some basics:

Magnetism. Ram Seshadri MRL 2031, x6129, Some basics: Magnetism Ram Seshadri MRL 2031, x6129, seshadri@mrl.ucsb.edu Some basics: A magnet is associated with magnetic lines of force, and a north pole and a south pole. he lines of force come out of the north

More information

Electrical spin-injection into semiconductors

Electrical spin-injection into semiconductors Electrical spin-injection into semiconductors L. W. Molenkamp Physikalisches Institut Universität Würzburg Am Hubland 97074 Würzburg Germany Contents Motivation The usual approach Theoretical treatment

More information

Current-driven Magnetization Reversal in a Ferromagnetic Semiconductor. (Ga,Mn)As/GaAs/(Ga,Mn)As Tunnel Junction

Current-driven Magnetization Reversal in a Ferromagnetic Semiconductor. (Ga,Mn)As/GaAs/(Ga,Mn)As Tunnel Junction Current-driven Magnetization Reversal in a Ferromagnetic Semiconductor (Ga,Mn)As/GaAs/(Ga,Mn)As Tunnel Junction D. Chiba 1, 2*, Y. Sato 1, T. Kita 2, 1, F. Matsukura 1, 2, and H. Ohno 1, 2 1 Laboratory

More information

Perpendicular MTJ stack development for STT MRAM on Endura PVD platform

Perpendicular MTJ stack development for STT MRAM on Endura PVD platform Perpendicular MTJ stack development for STT MRAM on Endura PVD platform Mahendra Pakala, Silicon Systems Group, AMAT Dec 16 th, 2014 AVS 2014 *All data in presentation is internal Applied generated data

More information

ORBITAL DIAGRAM - A graphical representation of the quantum number "map" of electrons around an atom.

ORBITAL DIAGRAM - A graphical representation of the quantum number map of electrons around an atom. 160 ORBITAL DIAGRAM - A graphical representation of the quantum number "map" of electrons around an atom. 4p 3d 4s 3p 3s 2p 2s 1s Each blank represents an ORBITAL, and can hold two electrons. The 4s subshell

More information

Lecture 11: Transition metals (1) Basics and magnetism

Lecture 11: Transition metals (1) Basics and magnetism Lecture 11: Transition metals (1) Basics and magnetism Oxidation states in transition metal compounds Ligand field theory Magnetism Susceptibility Temperature dependence Magnetic moments Figure: Wikipedia

More information

Giant Magnetoresistance

Giant Magnetoresistance Giant Magnetoresistance N. Shirato urse: Solid State Physics 2, Spring 2010, Instructor: Dr. Elbio Dagotto Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996

More information

CHAPTER 4. ELECTRONIC AND MAGNETIC PROPERTIES OF MX 2 (M = V, Nb; X = Al, Ga, In, Cl, Br AND I) COMPOUNDS IN CdI 2 -TYPE STRUCTURE

CHAPTER 4. ELECTRONIC AND MAGNETIC PROPERTIES OF MX 2 (M = V, Nb; X = Al, Ga, In, Cl, Br AND I) COMPOUNDS IN CdI 2 -TYPE STRUCTURE 84 CHAPTER 4 ELECTRONIC AND MAGNETIC PROPERTIES OF MX 2 (M = V, Nb; X = Al, Ga, In, Cl, Br AND I) COMPOUNDS IN CdI 2 -TYPE STRUCTURE 4.1 INTRODUCTION As ideal materials for use in spintronic devices, the

More information

Some pictures are taken from the UvA-VU Master Course: Advanced Solid State Physics by Anne de Visser (University of Amsterdam), Solid State Course

Some pictures are taken from the UvA-VU Master Course: Advanced Solid State Physics by Anne de Visser (University of Amsterdam), Solid State Course Some pictures are taken from the UvA-VU Master Course: Advanced Solid State Physics by Anne de Visser (University of Amsterdam), Solid State Course by Mark Jarrel (Cincinnati University), from Ibach and

More information

Chapter 1 Electronic and Photonic Materials - DMS. Diluted Magnetic Semiconductor (DMS)

Chapter 1 Electronic and Photonic Materials - DMS. Diluted Magnetic Semiconductor (DMS) Diluted Magnetic Semiconductor (DMS) 1 Properties of electron Useful! Charge Electron Spin? Mass 2 Schematic of a Spinning & Revolving Particle Spinning Revolution 3 Introduction Electronics Industry Uses

More information

Giant Magnetoresistance

Giant Magnetoresistance Giant Magnetoresistance 03/18/2010 Instructor: Dr. Elbio R. Dagotto Class: Solid State Physics 2 Nozomi Shirato Department of Materials Science and Engineering ntents: Giant Magnetoresistance (GMR) Discovery

More information

The Physics of Ferromagnetism

The Physics of Ferromagnetism Terunobu Miyazaki Hanmin Jin The Physics of Ferromagnetism Springer Contents Part I Foundation of Magnetism 1 Basis of Magnetism 3 1.1 Basic Magnetic Laws and Magnetic Quantities 3 1.1.1 Basic Laws of

More information

Self-compensating incorporation of Mn in Ga 1 x Mn x As

Self-compensating incorporation of Mn in Ga 1 x Mn x As Self-compensating incorporation of Mn in Ga 1 x Mn x As arxiv:cond-mat/0201131v1 [cond-mat.mtrl-sci] 9 Jan 2002 J. Mašek and F. Máca Institute of Physics, Academy of Sciences of the CR CZ-182 21 Praha

More information

Influence of exchange bias on magnetic losses in CoFeB/MgO/CoFeB tunnel junctions

Influence of exchange bias on magnetic losses in CoFeB/MgO/CoFeB tunnel junctions Influence of exchange bias on magnetic losses in CoFeB/MgO/CoFeB tunnel junctions Ryan Stearrett Ryan Stearrett, W. G. Wang, Xiaoming Kou, J. F. Feng, J. M. D. Coey, J. Q. Xiao, and E. R. Nowak, Physical

More information

Spin injection and absorption in antiferromagnets

Spin injection and absorption in antiferromagnets Spin injection and absorption in antiferromagnets L. Frangou (PhD), P. Merodio (PhD 2014), G. Forestier (Post-Doc), A. Ghosh, S. Oyarzún, S. Auffret, U. Ebels, M. Chshiev, H. Béa, L. Vila, O. Boulle, G.

More information

Materials Research for Advanced Data Storage

Materials Research for Advanced Data Storage Materials Research for Advanced Data Storage University of Alabama Center for Materials for Information Technology Fall Review November 18, 2002 Center for Materials for Information Technology (MINT) at

More information

-"l" also contributes ENERGY. Higher values for "l" mean the electron has higher energy.

-l also contributes ENERGY. Higher values for l mean the electron has higher energy. 175 - Giving the four parameters will uniquely identify an electron around an atom. No two electrons in the same atom can share all four. These parameters are called QUANTUM NUMBERS. PRINCIPAL QUANTUM

More information

Introduction to Heisenberg model. Javier Junquera

Introduction to Heisenberg model. Javier Junquera Introduction to Heisenberg model Javier Junquera Most important reference followed in this lecture Magnetism in Condensed Matter Physics Stephen Blundell Oxford Master Series in Condensed Matter Physics

More information

X-Ray Magnetic Dichroism. S. Turchini ISM-CNR

X-Ray Magnetic Dichroism. S. Turchini ISM-CNR X-Ray Magnetic Dichroism S. Turchini SM-CNR stefano.turchini@ism.cnr.it stefano.turchini@elettra.trieste.it Magnetism spin magnetic moment direct exchange: ferro antiferro superexchange 3d Ligand 2p 3d

More information

-"l" also contributes ENERGY. Higher values for "l" mean the electron has higher energy.

-l also contributes ENERGY. Higher values for l mean the electron has higher energy. 170 - Giving the four parameters will uniquely identify an electron around an atom. No two electrons in the same atom can share all four. These parameters are called QUANTUM NUMBERS. PRINCIPAL QUANTUM

More information

Chapter 6 Antiferromagnetism and Other Magnetic Ordeer

Chapter 6 Antiferromagnetism and Other Magnetic Ordeer Chapter 6 Antiferromagnetism and Other Magnetic Ordeer 6.1 Mean Field Theory of Antiferromagnetism 6.2 Ferrimagnets 6.3 Frustration 6.4 Amorphous Magnets 6.5 Spin Glasses 6.6 Magnetic Model Compounds TCD

More information

Lecture contents. Magnetic properties Diamagnetism Band paramagnetism Atomic paramagnetism Ferromagnetism. Molecular field theory Exchange interaction

Lecture contents. Magnetic properties Diamagnetism Band paramagnetism Atomic paramagnetism Ferromagnetism. Molecular field theory Exchange interaction 1 Lecture contents Magnetic properties Diamagnetism and paramagnetism Atomic paramagnetism Ferromagnetism Molecular field theory Exchange interaction NNSE 58 EM Lecture #1 [SI] M magnetization or magnetic

More information

Recent developments in spintronic

Recent developments in spintronic Recent developments in spintronic Tomas Jungwirth nstitute of Physics ASCR, Prague University of Nottingham in collaboration with Hitachi Cambridge, University of Texas, Texas A&M University - Spintronics

More information

Ferromagnetism and Electronic Transport. Ordinary magnetoresistance (OMR)

Ferromagnetism and Electronic Transport. Ordinary magnetoresistance (OMR) Ferromagnetism and Electronic Transport There are a number of effects that couple magnetization to electrical resistance. These include: Ordinary magnetoresistance (OMR) Anisotropic magnetoresistance (AMR)

More information

Electron spins in nonmagnetic semiconductors

Electron spins in nonmagnetic semiconductors Electron spins in nonmagnetic semiconductors Yuichiro K. Kato Institute of Engineering Innovation, The University of Tokyo Physics of non-interacting spins Optical spin injection and detection Spin manipulation

More information

Magnetic systems for refrigeration & thermometry

Magnetic systems for refrigeration & thermometry Magnetic systems for refrigeration & thermometry * Paramagnetic salts * * Hyperfine enhanced systems * * Nuclear spins * Magnetic moments can be aligned by external magnetic field Thermal disorder counteracts

More information

arxiv:cond-mat/ v1 7 Aug 1996

arxiv:cond-mat/ v1 7 Aug 1996 EXCHANGE COUPLING AND MAGNETIZATION PROFILES OF BINARY AND TERNARY MAGNETIC MULTILAYERS F. Süss, U. Krey 1 Institut für Physik II der Universität, D-93040 Regensburg, Germany arxiv:cond-mat/9608037v1 7

More information

Half-metallicity in Rhodium doped Chromium Phosphide: An ab-initio study

Half-metallicity in Rhodium doped Chromium Phosphide: An ab-initio study Half-metallicity in Rhodium doped Chromium Phosphide: An ab-initio study B. Amutha 1,*, R. Velavan 1 1 Department of Physics, Bharath Institute of Higher Education and Research (BIHER), Bharath University,

More information

SIMULATIONS ON DILUTE MAGNETIC SEMICONDUCTOR PROPERTIES

SIMULATIONS ON DILUTE MAGNETIC SEMICONDUCTOR PROPERTIES Romanian Reports in Physics, Vol. 62, No. 1, P. 115 120, 2010 SIMULATIONS ON DILUTE MAGNETIC SEMICONDUCTOR PROPERTIES M. NEGOITA, E. A. PATROI, C. V. ONICA National Institute for Research and Development

More information

μ (vector) = magnetic dipole moment (not to be confused with the permeability μ). Magnetism Electromagnetic Fields in a Solid

μ (vector) = magnetic dipole moment (not to be confused with the permeability μ). Magnetism Electromagnetic Fields in a Solid Magnetism Electromagnetic Fields in a Solid SI units cgs (Gaussian) units Total magnetic field: B = μ 0 (H + M) = μ μ 0 H B = H + 4π M = μ H Total electric field: E = 1/ε 0 (D P) = 1/εε 0 D E = D 4π P

More information

Temperature-dependence of magnetism of free Fe clusters

Temperature-dependence of magnetism of free Fe clusters Temperature-dependence of magnetism of free Fe clusters O. Šipr 1, S. Bornemann 2, J. Minár 2, S. Polesya 2, H. Ebert 2 1 Institute of Physics, Academy of Sciences CR, Prague, Czech Republic 2 Universität

More information

- A CHEMICAL BOND is a strong attractive force between the atoms in a compound. attractive forces between oppositely charged ions

- A CHEMICAL BOND is a strong attractive force between the atoms in a compound. attractive forces between oppositely charged ions CHEMICAL BONDS - A CHEMICAL BOND is a strong attractive force between the atoms in a compound. 3 TYPES OF CHEMICAL BOND Ionic bonds attractive forces between oppositely charged ions sodium chloride Covalent

More information

2 B B D (E) Paramagnetic Susceptibility. m s probability. A) Bound Electrons in Atoms

2 B B D (E) Paramagnetic Susceptibility. m s probability. A) Bound Electrons in Atoms Paramagnetic Susceptibility A) Bound Electrons in Atoms m s probability B +½ p ½e x Curie Law: 1/T s=½ + B ½ p + ½e +x With increasing temperature T the alignment of the magnetic moments in a B field is

More information

Igor A. Abrikosov Department of Physics, Chemistry, and Biology (IFM), Linköping University, Sweden

Igor A. Abrikosov Department of Physics, Chemistry, and Biology (IFM), Linköping University, Sweden Correlation between electronic structure, magnetism and physical properties of Fe-Cr alloys: ab initio modeling Igor A. Abrikosov Department of Physics, Chemistry, and Biology (IFM), Linköping University,

More information

Physics and applications (I)

Physics and applications (I) Spintronics: Physics and applications (I) Malek Zareyan IPM, 15 TiR 1387 1 Very weak magnetic changes give rise to major differences in resistance in a GMR system (.( ١٩٨٨ GMR has made possible miniaturizing

More information

5 Magnetic Sensors Introduction Theory. Applications

5 Magnetic Sensors Introduction Theory. Applications Sensor devices Magnetic sensors Outline 5 Magnetic Sensors Introduction Theory GalvanomagneticG Effects Applications Introduction A magnetic sensor is a transducer that converts a magnetic field into an

More information

Mesoscopic Spintronics

Mesoscopic Spintronics Mesoscopic Spintronics Taro WAKAMURA (Université Paris-Sud) Lecture 1 Today s Topics 1.1 History of Spintronics 1.2 Fudamentals in Spintronics Spin-dependent transport GMR and TMR effect Spin injection

More information

MSE 7025 Magnetic Materials (and Spintronics)

MSE 7025 Magnetic Materials (and Spintronics) MSE 7025 Magnetic Materials (and Spintronics) Lecture 4: Category of Magnetism Chi-Feng Pai cfpai@ntu.edu.tw Course Outline Time Table Week Date Lecture 1 Feb 24 Introduction 2 March 2 Magnetic units and

More information

Surface effects in frustrated magnetic materials: phase transition and spin resistivity

Surface effects in frustrated magnetic materials: phase transition and spin resistivity Surface effects in frustrated magnetic materials: phase transition and spin resistivity H T Diep (lptm, ucp) in collaboration with Yann Magnin, V. T. Ngo, K. Akabli Plan: I. Introduction II. Surface spin-waves,

More information

Luigi Paolasini

Luigi Paolasini Luigi Paolasini paolasini@esrf.fr LECTURE 4: MAGNETIC INTERACTIONS - Dipole vs exchange magnetic interactions. - Direct and indirect exchange interactions. - Anisotropic exchange interactions. - Interplay

More information

Interstitial Mn in (Ga,Mn)As: Hybridization with Conduction Band and Electron Mediated Exchange Coupling

Interstitial Mn in (Ga,Mn)As: Hybridization with Conduction Band and Electron Mediated Exchange Coupling Vol. 112 (2007) ACTA PHYSICA POLONICA A No. 2 Proceedings of the XXXVI International School of Semiconducting Compounds, Jaszowiec 2007 Interstitial Mn in (Ga,Mn)As: Hybridization with Conduction Band

More information

VIIIA He IIA IIIA IVA VA VIA VIIA. Li Be B C N O F Ne. Na Mg VIB VIIB VIIIB IB IIB S. K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br

VIIIA He IIA IIIA IVA VA VIA VIIA. Li Be B C N O F Ne. Na Mg VIB VIIB VIIIB IB IIB S. K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br 188 THE FIRST TWO PERIODIC TRENDS IN A NUTSHELL LARGER IONIZATION ENERGY SMALLER RADIUS IA H IIA IIIA IVA VA VIA VIIA VIIIA He Li Be B C N O F Ne Na Mg IIIB IVB VB Al Si P VIB VIIB VIIIB IB IIB S Cl Ar

More information

Systèmes Hybrides. Norman Birge Michigan State University

Systèmes Hybrides. Norman Birge Michigan State University Systèmes Hybrides Norman Birge Michigan State University Résumé Systèmes F/N Systèmes S/N Systèmes S/F Résumé: Systèmes F/N Accumulation de spin Giant Magnetoresistance (GMR) Spin-transfer torque (STT)

More information

Introduction to Spintronics and Spin Caloritronics. Tamara Nunner Freie Universität Berlin

Introduction to Spintronics and Spin Caloritronics. Tamara Nunner Freie Universität Berlin Introduction to Spintronics and Spin Caloritronics Tamara Nunner Freie Universität Berlin Outline Format of seminar How to give a presentation How to search for scientific literature Introduction to spintronics

More information

GMR Read head. Eric Fullerton ECE, CMRR. Introduction to recording Basic GMR sensor Next generation heads TMR, CPP-GMR UCT) Challenges ATE

GMR Read head. Eric Fullerton ECE, CMRR. Introduction to recording Basic GMR sensor Next generation heads TMR, CPP-GMR UCT) Challenges ATE GMR Read head Eric Fullerton ECE, CMRR Introduction to recording Basic GMR sensor Next generation heads TMR, CPP-GMR UCT) Challenges ATE 1 Product scaling 5 Mbyte 100 Gbyte mobile drive 8 Gbyte UCT) ATE

More information

Research Highlights. Salient results from our group. Mixed phosphides in Sn-P and Sn-Mn-P systems

Research Highlights. Salient results from our group. Mixed phosphides in Sn-P and Sn-Mn-P systems Research Highlights Dilute magnetic semiconductors and Spintronics Spintronics is a branch of electronics emerged from the dilute magnetic semiconductor in an aspect of utilization of the spin in addition

More information

Paramagnetism and Diamagnetism. Paramagnets (How do paramagnets differ fundamentally from ferromagnets?)

Paramagnetism and Diamagnetism. Paramagnets (How do paramagnets differ fundamentally from ferromagnets?) Paramagnetism and Diamagnetism Paramagnets (How do paramagnets differ fundamentally from ferromagnets?) The study of paramagnetism allows us to investigate the atomic magnetic moments of atoms almost in

More information

Magneto-Seebeck effect in spin-valve with in-plane thermal gradient

Magneto-Seebeck effect in spin-valve with in-plane thermal gradient Magneto-Seebeck effect in spin-valve with in-plane thermal gradient S. Jain 1, a), D. D. Lam 2, b), A. Bose 1, c), H. Sharma 3, d), V. R. Palkar 1, e), C. V. Tomy 3, f), Y. Suzuki 2, g) 1, h) and A. A.

More information

Giant Magnetoresistance

Giant Magnetoresistance GENERAL ARTICLE Giant Magnetoresistance Nobel Prize in Physics 2007 Debakanta Samal and P S Anil Kumar The 2007 Nobel Prize in Physics was awarded to Albert Fert and Peter Grünberg for the discovery of

More information

Energy Stabilities, Magnetic Properties, and Electronic Structures of Diluted Magnetic Semiconductor Zn 1 x Mn x S(001) Thin Films

Energy Stabilities, Magnetic Properties, and Electronic Structures of Diluted Magnetic Semiconductor Zn 1 x Mn x S(001) Thin Films CHINESE JOURNAL OF CHEMICAL PHYSICS VOLUME 24, NUMBER 1 FEBRUARY 27, 2011 ARTICLE Energy Stabilities, Magnetic Properties, and Electronic Structures of Diluted Magnetic Semiconductor Zn 1 x Mn x S(001)

More information

MSE 7025 Magnetic Materials (and Spintronics)

MSE 7025 Magnetic Materials (and Spintronics) MSE 7025 Magnetic Materials (and Spintronics) Lecture 14: Spin Transfer Torque And the future of spintronics research Chi-Feng Pai cfpai@ntu.edu.tw Course Outline Time Table Week Date Lecture 1 Feb 24

More information

201. The Nature o f the Metallic Bond. III

201. The Nature o f the Metallic Bond. III No. 8] 913 201. The Nature o f the Metallic Bond. III Atomic Interactions in Alloys. I By San-ichiro MIZUSHIMA, M.J.A., and Isao Ichishima Tokyo Research Institute, Yawata Iron and Steel Co. Ltd., Ida,

More information

- Some properties of elements can be related to their positions on the periodic table.

- Some properties of elements can be related to their positions on the periodic table. 186 PERIODIC TRENDS - Some properties of elements can be related to their positions on the periodic table. ATOMIC RADIUS - The distance between the nucleus of the atoms and the outermost shell of the electron

More information

复习题. 2 Calculate the intensity of magnetic field in the air gap of the magnetic circuit shown in the figure. Use the values N=200,

复习题. 2 Calculate the intensity of magnetic field in the air gap of the magnetic circuit shown in the figure. Use the values N=200, 复习题 1 Calculate the magnetic moment of a sphere of radius R made from a magnetic material with magnetic susceptibility, when it is magnetized by an external magnetic field H. How is the value of the moment

More information

SPINTRONICS. Waltraud Buchenberg. Faculty of Physics Albert-Ludwigs-University Freiburg

SPINTRONICS. Waltraud Buchenberg. Faculty of Physics Albert-Ludwigs-University Freiburg SPINTRONICS Waltraud Buchenberg Faculty of Physics Albert-Ludwigs-University Freiburg July 14, 2010 TABLE OF CONTENTS 1 WHAT IS SPINTRONICS? 2 MAGNETO-RESISTANCE STONER MODEL ANISOTROPIC MAGNETO-RESISTANCE

More information

lectures accompanying the book: Solid State Physics: An Introduction, by Philip ofmann (2nd edition 2015, ISBN-10: 3527412824, ISBN-13: 978-3527412822, Wiley-VC Berlin. www.philiphofmann.net 1 Bonds between

More information

Semiconductor Spintronics

Semiconductor Spintronics IEEE TRANSACTIONS ON NANOTECHNOLOGY, VOL. 1, NO. 1, MARCH 2002 19 Semiconductor Spintronics Hiro Akinaga and Hideo Ohno, Member, IEEE Abstract We review recent progress made in the field of semiconductor

More information

Magnetic tunnel junctions using Co-based Heusler alloy electrodes

Magnetic tunnel junctions using Co-based Heusler alloy electrodes Magnetic tunnel junctions using Co-based Heusler alloy electrodes 1 Half-metallic Heusler alloy thin films for spintronic devices E F E Energy gap Co 2 YZ: L2 1 structure 2a MgO.5957 nm a Co.5654 2MnSi

More information

The exchange interaction between FM and AFM materials

The exchange interaction between FM and AFM materials Chapter 1 The exchange interaction between FM and AFM materials When the ferromagnetic (FM) materials are contacted with antiferromagnetic (AFM) materials, the magnetic properties of FM materials are drastically

More information

Ferromagnetism in Cr-Doped GaN: A First Principles Calculation

Ferromagnetism in Cr-Doped GaN: A First Principles Calculation Ferromagnetism in Cr-Doped GaN: A First Principles Calculation G. P. Das, 1,2 B. K. Rao, 1 and P. Jena 1 1 Department of Physics, Virginia Commonwealth University Richmond, VA 23284-2000 2 Bhabha Atomic

More information

Atomic Theory and Atomic structure. Part A. d) Distance of electrons from the nucleus

Atomic Theory and Atomic structure. Part A. d) Distance of electrons from the nucleus Grade Subject Topic : AP : Science : Atomic Theory and Atomic Structure Atomic Theory and Atomic structure Part A (1) The Principal quantum number represents a) Shape of an orbital b) Number of electrons

More information

Topological Phases of the Spin-1/2 Ferromagnetic-Antiferromagnetic Alternating Heisenberg Chain with Frustrated Next-Nearest-Neighbour Interaction

Topological Phases of the Spin-1/2 Ferromagnetic-Antiferromagnetic Alternating Heisenberg Chain with Frustrated Next-Nearest-Neighbour Interaction Topological Phases of the Spin-1/2 Ferromagnetic-Antiferromagnetic Alternating Heisenberg Chain with Frustrated Next-Nearest-Neighbour Interaction Kazuo Hida (Saitama University) Ken ichi Takano (Toyota

More information

Giant Magnetoresistance

Giant Magnetoresistance Giant Magnetoresistance Zachary Barnett Course: Solid State II; Instructor: Elbio Dagotto; Semester: Spring 2008 Physics Department, University of Tennessee (Dated: February 24, 2008) This paper briefly

More information

From Hall Effect to TMR

From Hall Effect to TMR From Hall Effect to TMR 1 Abstract This paper compares the century old Hall effect technology to xmr technologies, specifically TMR (Tunnel Magneto-Resistance) from Crocus Technology. It covers the various

More information

Magnetism of 3d, 4d, and 5d transition-metal impurities on Pd 001 and Pt 001 surfaces

Magnetism of 3d, 4d, and 5d transition-metal impurities on Pd 001 and Pt 001 surfaces PHYSICAL REVIEW B VOLUME 53, NUMBER 4 15 JANUARY 1996-II Magnetism of 3d, 4d, and 5d transition-metal impurities on Pd 001 and Pt 001 surfaces V. S. Stepanyuk Max-Planck-Institut für Mikrostrukturphysik,

More information

Lecture 5. Chapters 3 & 4. Induced magnetization: that which is induced in the presence of an applied magnetic field. diamagnetic.

Lecture 5. Chapters 3 & 4. Induced magnetization: that which is induced in the presence of an applied magnetic field. diamagnetic. Lecture 5 Induced magnetization: that which is induced in the presence of an applied magnetic field diamagnetic paramagnetic Remanent magnetization: that which remains in the absence of an external field

More information

Magnetic Sensor (3B) Magnetism Hall Effect AMR Effect GMR Effect. Young Won Lim 9/23/09

Magnetic Sensor (3B) Magnetism Hall Effect AMR Effect GMR Effect. Young Won Lim 9/23/09 Magnetic Sensor (3B) Magnetism Hall Effect AMR Effect GMR Effect Copyright (c) 2009 Young W. Lim. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation

More information

Fe 1-x Co x Si, a Silicon Based Magnetic Semiconductor

Fe 1-x Co x Si, a Silicon Based Magnetic Semiconductor Fe 1-x Co x Si, a Silicon Based Magnetic Semiconductor T (K) 1 5 Fe.8 Co.2 Si ρ xy (µω cm) J.F. DiTusa N. Manyala LSU Y. Sidis D.P. Young G. Aeppli UCL Z. Fisk FSU T C 1 Nature Materials 3, 255-262 (24)

More information

A Study of the Group-IV Diluted Magnetic Semiconductor GeMn. Melissa Commisso Dolph Stu Wolf Group December 4 th, 2008

A Study of the Group-IV Diluted Magnetic Semiconductor GeMn. Melissa Commisso Dolph Stu Wolf Group December 4 th, 2008 A Study of the Group-IV Diluted Magnetic Semiconductor GeMn Melissa Commisso Dolph Stu Wolf Group December 4 th, 2008 Outline Motivation and Background Our DMS : GeMn Hall Bars Summary / Future Work Motivation

More information

- A CHEMICAL BOND is a strong attractive force between the atoms in a compound. attractive forces between oppositely charged ions

- A CHEMICAL BOND is a strong attractive force between the atoms in a compound. attractive forces between oppositely charged ions 191 CHEMICAL BONDS - A CHEMICAL BOND is a strong attractive force between the atoms in a compound. 3 TYPES OF CHEMICAL BOND Ionic bonds attractive forces between oppositely charged ions sodium chloride

More information

Semiconductors and Optoelectronics. Today Semiconductors Acoustics. Tomorrow Come to CH325 Exercises Tours

Semiconductors and Optoelectronics. Today Semiconductors Acoustics. Tomorrow Come to CH325 Exercises Tours Semiconductors and Optoelectronics Advanced Physics Lab, PHYS 3600 Don Heiman, Northeastern University, 2017 Today Semiconductors Acoustics Tomorrow Come to CH325 Exercises Tours Semiconductors and Optoelectronics

More information

Solutions and Ions. Pure Substances

Solutions and Ions. Pure Substances Class #4 Solutions and Ions CHEM 107 L.S. Brown Texas A&M University Pure Substances Pure substance: described completely by a single chemical formula Fixed composition 1 Mixtures Combination of 2 or more

More information

The Periodic Table. Periodic Properties. Can you explain this graph? Valence Electrons. Valence Electrons. Paramagnetism

The Periodic Table. Periodic Properties. Can you explain this graph? Valence Electrons. Valence Electrons. Paramagnetism Periodic Properties Atomic & Ionic Radius Energy Electron Affinity We want to understand the variations in these properties in terms of electron configurations. The Periodic Table Elements in a column

More information

Electronic structure, spin transport and magnetic anisotropy of selected cubic Heusler and hexagonal Heusler like alloys

Electronic structure, spin transport and magnetic anisotropy of selected cubic Heusler and hexagonal Heusler like alloys Electronic structure, spin transport and magnetic anisotropy of selected cubic Heusler and hexagonal Heusler like alloys O. Mryasov 1,2,3 S. Faleev 1,4, A. Kalitsov 1,3, J. Barker 1,5 1. MINT Center, University

More information

EXTRINSIC SEMICONDUCTOR

EXTRINSIC SEMICONDUCTOR EXTRINSIC SEMICONDUCTOR In an extrinsic semiconducting material, the charge carriers originate from impurity atoms added to the original material is called impurity [or] extrinsic semiconductor. This Semiconductor

More information

Making Semiconductors Ferromagnetic: Opportunities and Challenges

Making Semiconductors Ferromagnetic: Opportunities and Challenges Making Semiconductors Ferromagnetic: Opportunities and Challenges J.K. Furdyna University of Notre Dame Collaborators: X. Liu and M. Dobrowolska, University of Notre Dame T. Wojtowicz, Institute of Physics,

More information

First-Principles Calculation of Exchange Interactions

First-Principles Calculation of Exchange Interactions Chapter 2 First-Principles Calculation of Exchange Interactions Before introducing the first-principles methods for the calculation of exchange interactions in magnetic systems we will briefly review two

More information

Spin Current and Spin Seebeck Effect

Spin Current and Spin Seebeck Effect at Rome, Italy (September 18, 2013) Spin Current and Spin Seebeck Effect Sadamichi Maekawa Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA) at Tokai and CREST-JST. Co-workers:

More information

Low Energy Spin Transfer Torque RAM (STT-RAM / SPRAM) Zach Foresta April 23, 2009

Low Energy Spin Transfer Torque RAM (STT-RAM / SPRAM) Zach Foresta April 23, 2009 Low Energy Spin Transfer Torque RAM (STT-RAM / SPRAM) Zach Foresta April 23, 2009 Overview Background A brief history GMR and why it occurs TMR structure What is spin transfer? A novel device A future

More information

- Light has properties of WAVES such as DIFFRACTION (it bends around small obstructions).

- Light has properties of WAVES such as DIFFRACTION (it bends around small obstructions). 170 LIGHT wavelength Diffraction frequency = wavelengths / time = - Light has properties of WAVES such as DIFFRACTION (it bends around small obstructions). - Einstein noted that viewing light as a particle

More information

Physics of Magnetism. Chapter references are to Essentials of Paleomagnetism, UC Press, 2010

Physics of Magnetism. Chapter references are to Essentials of Paleomagnetism, UC Press, 2010 Physics of Magnetism Chapter references are to Essentials of Paleomagnetism, UC Press, 2010 http://magician.ucsd.edu/essentials 1 Magnetic units (sorry!) SI cgs Magnetic fields as the gradient of a scalar

More information

Conductivity of a disordered ferromagnetic monoatomic film

Conductivity of a disordered ferromagnetic monoatomic film Materials Science-Poland, Vol. 6, No. 4, 008 Conductivity of a disordered ferromagnetic monoatomic film A. PAJA *, B. J. SPISAK Faculty of Physics and Applied Computer Science, AGH University of Science

More information