Hyperfine interaction
|
|
- Heather Cobb
- 5 years ago
- Views:
Transcription
1 Hyperfine interaction The notion hyperfine interaction (hfi) comes from atomic physics, where it is used for the interaction of the electronic magnetic moment with the nuclear magnetic moment. In magnetic resonance this interaction is encountered frequently and is responsible for a number of important aspects of ESR and NMR spectra: In high resolution ESR spectroscopy of e.g. radicals in solution the hyperfine interaction leads to resolved hyperfine splitting of the ESR. If the hyperfine interaction is larger than other unresolved contributions to the ESR line width, the hyperfine splitting is resolved in the ESR of localised centres in the solid state. Unresolved hyperfine interactions with many coupled nuclei are often a major contribution to the ESR line widths in solid state ESR. If the electronic spin is exchanged rapidly due to the exchange interaction or the motion of conduction electrons, the NMR is shifted by the averaged hyperfine interaction of the electrons. This is the Knight shift of the NMR. GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt
2 The hyperfine interaction can be visualized as the motion of the electron in the magnetic dipole field of the nucleus. The nuclear magnetic moment leads to a magnetic field B n (r), which is called the nuclear field. The electronic magnetic moment interacts with this nuclear field B n (r). B 0 The interaction energy is: A = -µ e B n (r) B n There are two contributions: µ n µ e. The wave function ψ(r) of the electron does not vanish at the nuclear position ( s-states in atomic terminology). ψ(0) 0. A µ = 8π ( g µ ) ( g µ ) ψ(0) 4π 3 0 s n K e B This is the Fermi-contact interaction.. The wave function of the electron has an angular dependence and vanishes at the nuclear position: ψ(0) 0 (e.g. a p-function). A µ 4π 5 g g r 0 = ( p n µ ) ( ) 3cos K e µ B θ 3 Averaging over the electronic wave function GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt
3 If both contributions are present: A = A + A θ s p (3cos ) B 0 θ θ Is the angle between the magnetic field B 0 and the p-function lobe. p-function In gases and liquids, only the isotropic part A s is observable, since the rapid reorientation of the atoms or molecules averages the anisotropic contributions to zero. In the solid state, the site symmetry of the nuclear position is important: For cubic site symmetry, only A s is retained. In the general case: the interaction is a nd rank tensor, the hyperfine tensor. A = A sin θ cos Φ + A sin θ sin Φ + A cos θ XX YY ZZ θ and Φ are the angles between the coordinate system axes and the tensor principle axes X,Y,Z. GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 3
4 In general situations, an electronic spin S and a nuclear spin I are coupled by an interaction ˆ H = Iˆ A Sˆ The second rank tensor A is called the hyperfine tensor and it hfi can be described by its three principal axes values A XX, A YY, A ZZ along the principal axis system ^X,Y,Z. ^^ In many situations, the hyperfine interaction is a scalar, independent of the spin direction. This case is e.g. the Fermi contact interaction between s-like electrons at the nuclear site. In this situation, the hfi leads to a scalar interaction term: H ˆ = ai ˆ Sˆ = hai ˆ Sˆ The hfi coupling constant a = h A is often given in frequency units: e.g. A = 65 MHz. It is interesting to note at that point, that our fundamental definition and the experimental realisation of the time unit second is realised by the hyperfine interaction of the s-electron in 33 Cs with the nuclear magnetic moment of the Cs I=7/ nucleus. hfi B 0 Electron spin nuclear spin The Hamiltonian of an electronic spin ^ S and a nuclear spin ^I in a magnetic field B 0 along the z-direction: Hˆ = g µ BS ˆ g µ BI ˆ + hais ˆ ˆ e B 0 z n K 0 z GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 4
5 This Hamiltonian is solved by diagonalisation, leading to the energy eigenvalues and the eigenstates. As the base states for the quantum mechanical treatment, we take product states between the electron spin states S,m S > and the nuclear spin states I, m I > ψ = Sm, Im, m S = -S, -S+,,S-,S m I = -I, -I+,,I-,I S I There are (S+) (I+) base states. In order to avoid a too clumsy notation, one usually omits the S, I in the base states and writes: ψ = mm = m m S I S I For the case S =/ I =/, we have 4 base states: = + + = + 3 = + 4 = The operators S z and I z are diagonal in the base states. Sˆ z ˆ = Sz + + = + + = z ˆ S = + ˆ S z 3 = 3 S ˆ z = 4 4 ˆ I z = + I ˆ z = ˆ I z 3 = + 3 I ˆ z = 4 4 GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 5
6 H ˆ hfi = hai ˆ S ˆ = ha ( Iˆ ˆ ˆ ˆ ˆ ˆ x Sx + Iy Sy + Iz Sz) H hfi = ha Iˆ ˆ ˆ ˆ ˆ ˆ z Sz + ( I+ S- + I- S+ ) ˆ ( ) S ˆ 3 = S ˆ 4 = S ˆ = 3 S ˆ - = 4 I ˆ = I ˆ 4 = 3 I ˆ = I ˆ - 3 = 4 S operates on the electronic spin only leaving the nuclear spin state unaffected. Similarly I only operates on the nuclear spin. IS ˆ ˆ + - = I ˆ 4 + = 3 IS ˆ ˆ = Iˆ- = ˆ ( ) H = ha Iˆ Sˆ + ( Iˆ Sˆ ˆ ˆ - + I- S ) hfi z z + + Is diagonal with matrix elements ±ha/4 Couples the states > and 3> with matrix elements ha/ Note: For quantum mechanical calculations with spins, it is generally vary practical to express the operators S x, S y, I x, I y in terms of the shift operators S +, S -, I +, I -. The matrix elements of these operators are easy to evaluate: S + shifts a state m S > to m S +>, unless m S > is the highest state. S - shifts m S > to m S ->, unless m S > is the lowest state. GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 6
7 Matrix elements of the Hamilton operator H = g µ BS ˆ g µ BI ˆ + hais ˆ ˆ e B 0 z n K 0 z 3 4 = + + = + = + = = + + = + 3 = + 4 = geµ B B ha gnµ K B geµ B B 0 ha 0 0 ha + gnµ K B 0 4 geµ B B0 ha 0 0 ha gnµ K B 0 4 geµ B B ha + gnµ K B GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 7
8 E/h (GHz) 0 For high field B 0, the base states are practically the eigenstates of the Hamiltonian. Thus at high field, the states can be classified by >, > etc. > > B 0 /T > 3> GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 8
9 E/h (GHz) Selection rules for ESR-transitions: m S = ± m I = 0 > 3> and > 4> are the ESR transitions in high field B 0 > > B 0 /T -5-0 ESR spectrum B ha g µ e B 0 4> 3> GKMR ESR lecture WS005/06 Denninger B hyperfine_interaction.ppt 9
10 In low field B 0, the eigenstates clearly are no longer the base states. As the states are now a mixture of the 4 base states, there can be in principle 6 magnetic resonance transitions. However, it depends on the frequency E = h f, which are observed. f=ghz Transitions which apparently do not obey the selection rules m S = ±, m I = 0, are called A/h =.4 GHz f=ghz f=ghz B 0 /T forbidden transitions. However, there is nothing forbidden with these transitions. The states coupled by these transitions are mixtures of the base states, and the magnetic dipole transitions can occur with the correct selection rules. GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 0
11 What a the states in the limit of B 0 and B 0 = 0? The limit of very large B 0 is: the base states >, >, 3>, 4> are the eigenstates. States > and 3> have the S and I spin anti-parallel, thus they are lower in energy through the hyperfine interaction. Visualisation of the state coefficients 3 4 > > 4> 3> GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt
12 For B 0 = 0, the solutions are: a singlet with total spin 0 ( + + ) a triplet with total spin +,, + ( + ) + + These are very general properties of two spins coupled by an interaction of the form hai S. Triplet E=h A Singlet GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt
13 Visualisation of the coefficients of the states: 3 4 Negative coefficients are drawn downwards GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 3
14 The following operators are frequently found in calculations of spin systems: ˆ, ˆ z, ˆ x, ˆ ˆ ˆ y, +, - J J J J J J The quantum states are written as: JmJ The operator symbol J stands for any angular momentum operator like L, S, I, J = L+S, F = J+I etc. J is the spin number, m J the projection of the spin onto the quantisation axis, usually taken as the z-axis. Fundamental relations for the operators and the states are: ˆ J = ( + ) J Jm J J Jm J Jm = m Jm ˆz J J J J Diagonal with eigenvalue J(J+) Diagonal with eigenvalue m J J ˆ Jm J ( J ) m ( m ) Jm + + J = + + J J J Shifts one state up. Jˆ Jm J ( J ) m ( m ) Jm- J = + J J J ˆ ˆ ˆ + = Jx + ij J ˆ J ˆ ij ˆ = x y y J ˆ ( ˆ ˆ x J J ) = + + y + J J ˆ = i ( J ˆ J ˆ ) Shifts one state down. GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 4
15 Whereas the diagonal operators can easily be calculated, matrix element tables for the operators J + and J - are very convenient for practical quantum mechanical calculations. J J, J + -/> +/> <-/ <-5/ <-3/ <-/ <+/ <+3/ <+5/ <+/, J J, J + -> 0> +> <- < 0 < /> -3/> -/> +/> +3/> +5/> J, J + <- <- < 0 <+ <+ J, J + -3/> -/> +/> +3/> <-3/ <-/ <+/ <+3/ > -> 0> +> +> GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 5
16 J, J + <-3 <- <- < 0 <+ <+ <+3-3> -> -> 0> +> +> +3> J=7/ J, J + <-7/ <-5/ <-3/ <-/ <+/ <+3/ <+5/ <+7/ J=3-7/> -5/> -3/> -/> +/> +3/> +5/> +7/> GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 6
17 Hyperfine interaction in high field B 0 : if the electron Zeeman energy g e µ B B 0 is large compared to the hyperfine interaction, than the analysis is relatively simple: The electronic spin is quantized along the axis z of the magnetic field B 0. The electronic field B e acting on the nuclei is either in the same direction as or opposed to B 0, and the nuclear spin is quantized along z as well. The hyperfine interaction is thus ±ha/4, depending on parallel or anti-parallel spins. In mathematical terms this means, that only the diagonal matrix elements of the operators have to be taken into account. The eigenstates are the base states >, >, 3>, 4>. E = + + = + ha geµ B B 0 gnµ K B ha geµ B B + 0 gnµ K B 0 4 ha gµ B + e B 0 gµ B ha e B 0 4 = 3 = + ha + geµ B B + 0 gnµ K B0 4 ha geµ B B 0 gnµ K B0 4 GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 7
18 The ESR signal consists of two lines, the splitting is ha measured in field units. ESR signal st derivative B 0 B = ha g µ e B Note: the nuclear Zeeman energy plays no role in high fields, since the nuclear spin is not flipped in an ESR transition. If the hyperfine interaction is resolved in the ESR-spectrum, it can be directly read of the spectrum. Unfortunately, the hyperfine interaction is often small and not resolved, and very often there is hyperfine coupling to many nuclei, making the ESR spectrum fairly complicated. GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 8
19 Coupling with one nuclear spin I : I+ equidistant lines of practically equal intensity ESR signal ( st der.) I=3/ Magnetic field offset (mt) GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 9
20 Hyperfine interaction with a number of equivalent nuclei Without hyperfine coupling x I=/ ESR signal ( st der.) ESR signal ( st der.) Magnetic field offset (mt) Magnetic Field offset (mt) x I=/ x I=/ ESR signal ( st der.) ESR signal ( st der.) Magnetic Field offset (mt) Magnetic Field offset (mt) GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 0
21 The hyperfine structure is only resolved in the ESR spectra if A > line width. atom I e B H 3 C 9 F 9 Si 35 Cl ha /( g µ ) s As / 50.8 mt 4 MHz /.0 mt 3.08 GHz / 70.0 mt 48.6 GHz /.8 mt 3.4 GHz 3/ 66.5 mt 4.66 GHz Selected atomic values for the hyperfine interaction Calculated values for the complete periodic table: J.R. Morton, K.F. Preston, Journal of Magnetic Resonance 30, 577 (978) GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt
22 S=/, I= 6 states Spectrum in low field: 3 lines Not quite equidistant GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt
23 Spectrum in high field: 3 equidistant lines. GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 3
24 High resolution hyperfine spectra of radicals in solution DPPH: α, α -diphenyl-β-picryl hydrazyl Main coupling: equivalent N-atoms with I=. 5 lines. Small couplings: to the protons. α-pentachlorophenyl, α-phenylβ-picryl hydrazyl GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 4
25 GKMR ESR lecture WS005/06 Denninger hyperfine_interaction.ppt 5
In this lecture, we will go through the hyperfine structure of atoms. The coupling of nuclear and electronic total angular momentum is explained.
Lecture : Hyperfine Structure of Spectral Lines: Page- In this lecture, we will go through the hyperfine structure of atoms. Various origins of the hyperfine structure are discussed The coupling of nuclear
More informationSpin Interactions. Giuseppe Pileio 24/10/2006
Spin Interactions Giuseppe Pileio 24/10/2006 Magnetic moment µ = " I ˆ µ = " h I(I +1) " = g# h Spin interactions overview Zeeman Interaction Zeeman interaction Interaction with the static magnetic field
More information1.b Bloch equations, T 1, T 2
1.b Bloch equations, T 1, T Magnetic resonance eperiments are usually conducted with a large number of spins (at least 1 8, more typically 1 1 to 1 18 spins for electrons and 1 18 or more nuclear spins).
More informationMASSACHUSETTS INSTITUTE OF TECHNOLOGY 5.76 Modern Topics in Physical Chemistry Spring, Problem Set #2
Reading Assignment: Bernath Chapter 5 MASSACHUSETTS INSTITUTE O TECHNOLOGY 5.76 Modern Topics in Physical Chemistry Spring 994 Problem Set # The following handouts also contain useful information: C &
More informationMagentic Energy Diagram for A Single Electron Spin and Two Coupled Electron Spins. Zero Field.
7. Examples of Magnetic Energy Diagrams. There are several very important cases of electron spin magnetic energy diagrams to examine in detail, because they appear repeatedly in many photochemical systems.
More informationMagnetic Resonance Spectroscopy ( )
Magnetic Resonance Spectroscopy In our discussion of spectroscopy, we have shown that absorption of E.M. radiation occurs on resonance: When the frequency of applied E.M. field matches the energy splitting
More informationIntroduction to Electron Paramagnetic Resonance Spectroscopy
Introduction to Electron Paramagnetic Resonance Spectroscopy Art van der Est, Department of Chemistry, Brock University St. Catharines, Ontario, Canada 1 EPR Spectroscopy EPR is magnetic resonance on unpaired
More informationCourse Magnetic Resonance
Course Magnetic Resonance 9 9 t t evolution detection -SASL O N O C O O g (B) g'(b) 3X 3Y 3Z B Alanine Valine Dr. M.A. Hemminga Wageningen University Laboratory of Biophysics Web site: http://ntmf.mf.wau.nl/hemminga/
More information(b) The wavelength of the radiation that corresponds to this energy is 6
Chapter 7 Problem Solutions 1. A beam of electrons enters a uniform 1.0-T magnetic field. (a) Find the energy difference between electrons whose spins are parallel and antiparallel to the field. (b) Find
More informationAppendix II - 1. Figure 1: The splitting of the spin states of an unpaired electron
Appendix II - 1 May 2017 Appendix II: Introduction to EPR Spectroscopy There are several general texts on this topic, and this appendix is only intended to give you a brief outline of the Electron Spin
More informationLecture #13 1. Incorporating a vector potential into the Hamiltonian 2. Spin postulates 3. Description of spin states 4. Identical particles in
Lecture #3. Incorporating a vector potential into the Hamiltonian. Spin postulates 3. Description of spin states 4. Identical particles in classical and QM 5. Exchange degeneracy - the fundamental problem
More informationProblem Set 2 Due Tuesday, September 27, ; p : 0. (b) Construct a representation using five d orbitals that sit on the origin as a basis: 1
Problem Set 2 Due Tuesday, September 27, 211 Problems from Carter: Chapter 2: 2a-d,g,h,j 2.6, 2.9; Chapter 3: 1a-d,f,g 3.3, 3.6, 3.7 Additional problems: (1) Consider the D 4 point group and use a coordinate
More informationNMR: Formalism & Techniques
NMR: Formalism & Techniques Vesna Mitrović, Brown University Boulder Summer School, 2008 Why NMR? - Local microscopic & bulk probe - Can be performed on relatively small samples (~1 mg +) & no contacts
More informationCoupling of Angular Momenta Isospin Nucleon-Nucleon Interaction
Lecture 5 Coupling of Angular Momenta Isospin Nucleon-Nucleon Interaction WS0/3: Introduction to Nuclear and Particle Physics,, Part I I. Angular Momentum Operator Rotation R(θ): in polar coordinates the
More informationRotational Raman Spectroscopy
Rotational Raman Spectroscopy If EM radiation falls upon an atom or molecule, it may be absorbed if the energy of the radiation corresponds to the separation of two energy levels of the atoms or molecules.
More informationA.1 Alkaline atoms in magnetic fields
164 Appendix the Kohn, virial and Bertrand s theorem, with an original approach. Annex A.4 summarizes elements of the elastic collisions theory required to address scattering problems. Eventually, annex
More informationTHEORY OF MAGNETIC RESONANCE
THEORY OF MAGNETIC RESONANCE Second Edition Charles P. Poole, Jr., and Horacio A. Farach Department of Physics University of South Carolina, Columbia A Wiley-lnterscience Publication JOHN WILEY & SONS
More informationDirect dipolar interaction - utilization
Direct dipolar interaction - utilization Two main uses: I: magnetization transfer II: probing internuclear distances Direct dipolar interaction - utilization Probing internuclear distances ˆ hetero D d
More information5.61 Physical Chemistry Lecture #36 Page
5.61 Physical Chemistry Lecture #36 Page 1 NUCLEAR MAGNETIC RESONANCE Just as IR spectroscopy is the simplest example of transitions being induced by light s oscillating electric field, so NMR is the simplest
More informationRotations and vibrations of polyatomic molecules
Rotations and vibrations of polyatomic molecules When the potential energy surface V( R 1, R 2,..., R N ) is known we can compute the energy levels of the molecule. These levels can be an effect of: Rotation
More informationAn introduction to Solid State NMR and its Interactions
An introduction to Solid State NMR and its Interactions From tensor to NMR spectra CECAM Tutorial September 9 Calculation of Solid-State NMR Parameters Using the GIPAW Method Thibault Charpentier - CEA
More informationAlkali metals show splitting of spectral lines in absence of magnetic field. s lines not split p, d lines split
Electron Spin Electron spin hypothesis Solution to H atom problem gave three quantum numbers, n,, m. These apply to all atoms. Experiments show not complete description. Something missing. Alkali metals
More informationtakes the values:, +
rof. Dr. I. Nasser hys- (T-) February, 4 Angular Momentum Coupling Schemes We have so far considered only the coupling of the spin and orbital momentum of a single electron by means of the spin-orbit interaction.
More information( ). Expanding the square and keeping in mind that
One-electron atom in a Magnetic Field When the atom is in a magnetic field the magnetic moment of the electron due to its orbital motion and its spin interacts with the field and the Schrodinger Hamiltonian
More informatione 2m e c I, (7.1) = g e β B I(I +1), (7.2) = erg/gauss. (7.3)
Chemistry 126 Molecular Spectra & Molecular Structure Week # 7 Electron Spin Resonance Spectroscopy, Supplement Like the hydrogen nucleus, an unpaired electron in a sample has a spin of I=1/2. The magnetic
More information2.4. Quantum Mechanical description of hydrogen atom
2.4. Quantum Mechanical description of hydrogen atom Atomic units Quantity Atomic unit SI Conversion Ang. mom. h [J s] h = 1, 05459 10 34 Js Mass m e [kg] m e = 9, 1094 10 31 kg Charge e [C] e = 1, 6022
More information16. Reactions of the Radical Pairs. The I P Step of the Paradigm
16. Reactions of the Radical Pairs. The I P Step of the Paradigm Let us consider the product forming step in the general photochemical paradigm, i.e., the I P process shown in Figure 1. From the discussion
More informationQuantum chemical modelling of molecular properties - parameters of EPR spectra
Quantum chemical modelling of molecular properties - parameters of EPR spectra EPR ( electric paramagnetic resonance) spectra can be obtained only for open-shell systems, since they rely on transitions
More informationSynthesis of a Radical Trap
Chemistry Catalyzed oxidation with hydrogen peroxide Trapping of a free radical (spin trapping) Technique Acquisition and interpretation of ESR spectra Radical trap molecule that reacts with short-lived
More informationCrystal field and spin-orbit interaction
Crstal field and spin-orbit interaction In the solid state, there are two iportant contributions doinating the spin properties of the individual atos/ions: 1. Crstal field The crstal field describes the
More informationSolutions Final exam 633
Solutions Final exam 633 S.J. van Enk (Dated: June 9, 2008) (1) [25 points] You have a source that produces pairs of spin-1/2 particles. With probability p they are in the singlet state, ( )/ 2, and with
More informationNuclear magnetic resonance in condensed matter
University of Ljubljana Faculty of mathematics and physics Physics department SEMINAR Nuclear magnetic resonance in condensed matter Author: Miha Bratkovič Mentor: prof. dr. Janez Dolinšek Ljubljana, October
More informationAn Introduction to Hyperfine Structure and Its G-factor
An Introduction to Hyperfine Structure and Its G-factor Xiqiao Wang East Tennessee State University April 25, 2012 1 1. Introduction In a book chapter entitled Model Calculations of Radiation Induced Damage
More informationElectron spin resonance
Quick reference guide Introduction This is a model experiment for electron spin resonance, for clear demonstration of interaction between the magnetic moment of the electron spin with a superimposed direct
More informationAtomic Physics 3 rd year B1
Atomic Physics 3 rd year B1 P. Ewart Lecture notes Lecture slides Problem sets All available on Physics web site: http:www.physics.ox.ac.uk/users/ewart/index.htm Atomic Physics: Astrophysics Plasma Physics
More information(relativistic effects kinetic energy & spin-orbit coupling) 3. Hyperfine structure: ) (spin-spin coupling of e & p + magnetic moments) 4.
4 Time-ind. Perturbation Theory II We said we solved the Hydrogen atom exactly, but we lied. There are a number of physical effects our solution of the Hamiltonian H = p /m e /r left out. We already said
More informationHONOUR SCHOOL OF NATURAL SCIENCE. Final Examination GENERAL PHYSICAL CHEMISTRY I. Answer FIVE out of nine questions
HONOUR SCHOOL OF NATURAL SCIENCE Final Examination GENERAL PHYSICAL CHEMISTRY I Monday, 12 th June 2000, 9.30 a.m. - 12.30 p.m. Answer FIVE out of nine questions The numbers in square brackets indicate
More informationElectron Paramagnetic Resonance
Electron Paramagnetic Resonance Nikki Truss February 8, 2013 Abstract In this experiment a sample of DPPH inside an RF coil, within a Helmholtz coil arrangement, was used to investigate electron paramagnetic
More informationCondensed Matter Physics Prof. G. Rangarajan Department of Physics Indian Institute of Technology, Madras
(Refer Slide Time: 00:22) Condensed Matter Physics Prof. G. Rangarajan Department of Physics Indian Institute of Technology, Madras Lecture 25 Pauli paramagnetism and Landau diamagnetism So far, in our
More informationBiochemistry 530 NMR Theory and Practice
Biochemistry 530 NMR Theory and Practice Gabriele Varani Department of Biochemistry and Department of Chemistry University of Washington 1D spectra contain structural information.. but is hard to extract:
More informationPhysics 221A Fall 1996 Notes 21 Hyperfine Structure in Hydrogen and Alkali Atoms
Physics 221A Fall 1996 Notes 21 Hyperfine Structure in Hydrogen and Alkali Atoms Hyperfine effects in atomic physics are due to the interaction of the atomic electrons with the electric and magnetic multipole
More informationProblem Set 2 Due Thursday, October 1, & & & & # % (b) Construct a representation using five d orbitals that sit on the origin as a basis:
Problem Set 2 Due Thursday, October 1, 29 Problems from Cotton: Chapter 4: 4.6, 4.7; Chapter 6: 6.2, 6.4, 6.5 Additional problems: (1) Consider the D 3h point group and use a coordinate system wherein
More informationChapter 10: Multi- Electron Atoms Optical Excitations
Chapter 10: Multi- Electron Atoms Optical Excitations To describe the energy levels in multi-electron atoms, we need to include all forces. The strongest forces are the forces we already discussed in Chapter
More informationChapter 8 Magnetic Resonance
Chapter 8 Magnetic Resonance 9.1 Electron paramagnetic resonance 9.2 Ferromagnetic resonance 9.3 Nuclear magnetic resonance 9.4 Other resonance methods TCD March 2007 1 A resonance experiment involves
More informationChem8028(1314) - Spin Dynamics: Spin Interactions
Chem8028(1314) - Spin Dynamics: Spin Interactions Malcolm Levitt see also IK m106 1 Nuclear spin interactions (diamagnetic materials) 2 Chemical Shift 3 Direct dipole-dipole coupling 4 J-coupling 5 Nuclear
More informationPhysics 221A Fall 2005 Homework 11 Due Thursday, November 17, 2005
Physics 221A Fall 2005 Homework 11 Due Thursday, November 17, 2005 Reading Assignment: Sakurai pp. 234 242, 248 271, Notes 15. 1. Show that Eqs. (15.64) follow from the definition (15.61) of an irreducible
More informationChem 442 Review for Exam 2. Exact separation of the Hamiltonian of a hydrogenic atom into center-of-mass (3D) and relative (3D) components.
Chem 44 Review for Exam Hydrogenic atoms: The Coulomb energy between two point charges Ze and e: V r Ze r Exact separation of the Hamiltonian of a hydrogenic atom into center-of-mass (3D) and relative
More informationReading. What is EPR (ESR)? Spectroscopy: The Big Picture. Electron Paramagnetic Resonance: Hyperfine Interactions. Chem 634 T.
Electron Paramagnetic Resonance: yperfine Interactions hem 63 T. ughbanks Reading Drago s Physical Methods for hemists is still a good text for this section; it s available by download (zipped, password
More informationESR spectroscopy of catalytic systems - a primer
ESR spectroscopy of catalytic systems - a primer Thomas Risse Fritz-Haber-Institute of Max-Planck Society Department of Chemical Physics Faradayweg 4-6 14195 Berlin T. Risse, 3/22/2005, 1 ESR spectroscopy
More information5.61 Physical Chemistry Lecture #35+ Page 1
5.6 Physical Chemistry Lecture #35+ Page NUCLEAR MAGNETIC RESONANCE ust as IR spectroscopy is the simplest example of transitions being induced by light s oscillating electric field, so NMR is the simplest
More informationSpectra of Atoms and Molecules, 3 rd Ed., Peter F. Bernath, Oxford University Press, chapter 5. Engel/Reid, chapter 18.3 / 18.4
Last class Today Atomic spectroscopy (part I) Absorption spectroscopy Bohr model QM of H atom (review) Atomic spectroscopy (part II)-skipped Visualization of wave functions Atomic spectroscopy (part III)
More information1.a Magnetic Resonance in Solids
.a Magnetic Resonance in Solids The methods of Magnetic Resonance (MR) measure with high sensitivity the magnetic dipole moments and their couplings to the environment. nce the coupling between the magnetic
More informationSuperoperators for NMR Quantum Information Processing. Osama Usman June 15, 2012
Superoperators for NMR Quantum Information Processing Osama Usman June 15, 2012 Outline 1 Prerequisites 2 Relaxation and spin Echo 3 Spherical Tensor Operators 4 Superoperators 5 My research work 6 References.
More informationSolid-state NMR of spin > 1/2
Solid-state NMR of spin > 1/2 Nuclear spins with I > 1/2 possess an electrical quadrupole moment. Anisotropic Interactions Dipolar Interaction 1 H- 1 H, 1 H- 13 C: typically 50 khz Anisotropy of the chemical
More informationG : Quantum Mechanics II
G5.666: Quantum Mechanics II Notes for Lecture 7 I. A SIMPLE EXAMPLE OF ANGULAR MOMENTUM ADDITION Given two spin-/ angular momenta, S and S, we define S S S The problem is to find the eigenstates of the
More informationLecture #6 NMR in Hilbert Space
Lecture #6 NMR in Hilbert Space Topics Review of spin operators Single spin in a magnetic field: longitudinal and transverse magnetiation Ensemble of spins in a magnetic field RF excitation Handouts and
More informationMany-Electron Atoms. Thornton and Rex, Ch. 8
Many-Electron Atoms Thornton and Rex, Ch. 8 In principle, can now solve Sch. Eqn for any atom. In practice, -> Complicated! Goal-- To explain properties of elements from principles of quantum theory (without
More informationNMR Shifts. I Introduction and tensor/crystal symmetry.
NMR Shifts. I Introduction and tensor/crystal symmetry. These notes were developed for my group as introduction to NMR shifts and notation. 1) Basic shift definitions and notation: For nonmagnetic materials,
More informationNomenclature: Electron Paramagnetic Resonance (EPR) Electron Magnetic Resonance (EMR) Electron Spin Resonance (ESR)
Introduction to EPR Spectroscopy EPR allows paramagnetic species to be identified and their electronic and geometrical structures to be characterised Interactions with other molecules, concentrations,
More informationAddition of Angular Momenta
Addition of Angular Momenta What we have so far considered to be an exact solution for the many electron problem, should really be called exact non-relativistic solution. A relativistic treatment is needed
More informationIndirect Coupling. aka: J-coupling, indirect spin-spin coupling, indirect dipole-dipole coupling, mutual coupling, scalar coupling (liquids only)
Indirect Coupling aka: J-coupling, indirect spin-spin coupling, indirect dipole-dipole coupling, mutual coupling, scalar coupling (liquids only) First, two comments about direct coupling Nuclear spins
More informationStructure of diatomic molecules
Structure of diatomic molecules January 8, 00 1 Nature of molecules; energies of molecular motions Molecules are of course atoms that are held together by shared valence electrons. That is, most of each
More informationNMR Dynamics and Relaxation
NMR Dynamics and Relaxation Günter Hempel MLU Halle, Institut für Physik, FG Festkörper-NMR 1 Introduction: Relaxation Two basic magnetic relaxation processes: Longitudinal relaxation: T 1 Relaxation Return
More informationLS coupling. 2 2 n + H s o + H h f + H B. (1) 2m
LS coupling 1 The big picture We start from the Hamiltonian of an atomic system: H = [ ] 2 2 n Ze2 1 + 1 e 2 1 + H s o + H h f + H B. (1) 2m n e 4πɛ 0 r n 2 4πɛ 0 r nm n,m Here n runs pver the electrons,
More informationSpin Dynamics Basics of Nuclear Magnetic Resonance. Malcolm H. Levitt
Spin Dynamics Basics of Nuclear Magnetic Resonance Second edition Malcolm H. Levitt The University of Southampton, UK John Wiley &. Sons, Ltd Preface xxi Preface to the First Edition xxiii Introduction
More informationAtomic and molecular physics Revision lecture
Atomic and molecular physics Revision lecture Answer all questions Angular momentum J`2 ` J z j,m = j j+1 j,m j,m =m j,m Allowed values of mgo from j to +jin integer steps If there is no external field,
More informationBackground: In this chapter we will discuss the interaction of molecules with a magnetic field.
Chapter 4 NMR Background: In this chapter we will discuss the interaction of molecules with a magnetic field. * Nuclear Spin Angular Momenta - recall electrons & spin -- our spin functions are and which
More informationSommerfeld (1920) noted energy levels of Li deduced from spectroscopy looked like H, with slight adjustment of principal quantum number:
Spin. Historical Spectroscopy of Alkali atoms First expt. to suggest need for electron spin: observation of splitting of expected spectral lines for alkali atoms: i.e. expect one line based on analogy
More information6.1 Nondegenerate Perturbation Theory
6.1 Nondegenerate Perturbation Theory Analytic solutions to the Schrödinger equation have not been found for many interesting systems. Fortunately, it is often possible to find expressions which are analytic
More informationESR spectroscopy of catalytic systems - a primer
ESR spectroscopy of catalytic systems - a primer Thomas Risse Fritz-Haber-Institute of Max-Planck Society Department of Chemical Physics Faradayweg 4-6 14195 Berlin T. Risse, 11/6/2007, 1 ESR spectroscopy
More informationMany-Electron Atoms. Thornton and Rex, Ch. 8
Many-Electron Atoms Thornton and Rex, Ch. 8 In principle, can now solve Sch. Eqn for any atom. In practice, -> Complicated! Goal-- To explain properties of elements from principles of quantum theory (without
More information5.80 Small-Molecule Spectroscopy and Dynamics
MIT OpenCourseWare http://ocw.mit.edu 5.80 Small-Molecule Spectroscopy and Dynamics Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 5.80 Lecture
More informationMagnetism in low dimensions from first principles. Atomic magnetism. Gustav Bihlmayer. Gustav Bihlmayer
IFF 10 p. 1 Magnetism in low dimensions from first principles Atomic magnetism Gustav Bihlmayer Institut für Festkörperforschung, Quantum Theory of Materials Gustav Bihlmayer Institut für Festkörperforschung
More informationSolid-state NMR and proteins : basic concepts (a pictorial introduction) Barth van Rossum,
Solid-state NMR and proteins : basic concepts (a pictorial introduction) Barth van Rossum, 16.02.2009 Solid-state and solution NMR spectroscopy have many things in common Several concepts have been/will
More informationOn Electron Paramagnetic Resonance in DPPH
On Electron Paramagnetic Resonance in DPPH Shane Duane ID: 08764522 JS Theoretical Physics 5th Dec 2010 Abstract Electron Paramagnetic Resonance (EPR) was investigated in diphenyl pecryl hydrazyl (DPPH).
More information221B Lecture Notes Many-Body Problems I (Quantum Statistics)
221B Lecture Notes Many-Body Problems I (Quantum Statistics) 1 Quantum Statistics of Identical Particles If two particles are identical, their exchange must not change physical quantities. Therefore, a
More information6 NMR Interactions: Zeeman and CSA
6 NMR Interactions: Zeeman and CSA 6.1 Zeeman Interaction Up to this point, we have mentioned a number of NMR interactions - Zeeman, quadrupolar, dipolar - but we have not looked at the nature of these
More informationNMR Nuclear Magnetic Resonance Spectroscopy p. 83. a hydrogen nucleus (a proton) has a charge, spread over the surface
NMR Nuclear Magnetic Resonance Spectroscopy p. 83 a hydrogen nucleus (a proton) has a charge, spread over the surface a spinning charge produces a magnetic moment (a vector = direction + magnitude) along
More informationNuclear Magnetic Resonance (NMR) Spectroscopy Introduction:
Nuclear Magnetic Resonance (NMR) Spectroscopy Introduction: Nuclear magnetic resonance spectroscopy (NMR) is the most powerful tool available for organic structure determination. Like IR spectroscopy,
More informationNuclear Magnetic Resonance Spectroscopy
Nuclear Magnetic Resonance Spectroscopy Ecole Polytechnique Département de Chimie CHI 551 Dr. Grégory Nocton Bureau 01 30 11 A Tel: 44 02 Ecole polytechnique / CNRS Laboratoire de Chimie Moléculaire E-mail:
More informationElectron Paramagnetic Resonance parameters from Wave Function Theory calculations. Laboratoire de Chimie et de Physique Quantiques Toulouse
Electron Paramagnetic Resonance parameters from Wave Function Theory calculations Hélène Bolvin Laboratoire de Chimie et de Physique Quantiques Toulouse Outline Preliminaries EPR spectroscopy spin Hamiltonians
More informationMAGNETISM OF ATOMS QUANTUM-MECHANICAL BASICS. Janusz Adamowski AGH University of Science and Technology, Kraków, Poland
MAGNETISM OF ATOMS QUANTUM-MECHANICAL BASICS Janusz Adamowski AGH University of Science and Technology, Kraków, Poland 1 The magnetism of materials can be derived from the magnetic properties of atoms.
More informationClassical behavior of magnetic dipole vector. P. J. Grandinetti
Classical behavior of magnetic dipole vector Z μ Y X Z μ Y X Quantum behavior of magnetic dipole vector Random sample of spin 1/2 nuclei measure μ z μ z = + γ h/2 group μ z = γ h/2 group Quantum behavior
More informationNuclear Quadrupole Resonance Spectroscopy. Some examples of nuclear quadrupole moments
Nuclear Quadrupole Resonance Spectroscopy Review nuclear quadrupole moments, Q A negative value for Q denotes a distribution of charge that is "football-shaped", i.e. a sphere elongated at the poles; a
More informationQuantum Physics II (8.05) Fall 2002 Assignment 12 and Study Aid
Quantum Physics II (8.05) Fall 2002 Assignment 12 and Study Aid Announcement This handout includes 9 problems. The first 5 are the problem set due. The last 4 cover material from the final few lectures
More informationElectronic Spectra of Complexes
Electronic Spectra of Complexes Interpret electronic spectra of coordination compounds Correlate with bonding Orbital filling and electronic transitions Electron-electron repulsion Application of MO theory
More informationNuclear models: Collective Nuclear Models (part 2)
Lecture 4 Nuclear models: Collective Nuclear Models (part 2) WS2012/13: Introduction to Nuclear and Particle Physics,, Part I 1 Reminder : cf. Lecture 3 Collective excitations of nuclei The single-particle
More information9. Transitions between Magnetic Levels Spin Transitions Between Spin States. Conservation of Spin Angular Momentum
9. Transitions between Magnetic Levels pin Transitions Between pin tates. Conservation of pin Angular Momentum From the magnetic energy diagram derived in the previous sections (Figures 14, 15 and 16),
More informationChem 442 Review of Spectroscopy
Chem 44 Review of Spectroscopy General spectroscopy Wavelength (nm), frequency (s -1 ), wavenumber (cm -1 ) Frequency (s -1 ): n= c l Wavenumbers (cm -1 ): n =1 l Chart of photon energies and spectroscopies
More informationElectron Paramagnetic Resonance. Ferro Magnetic Resonance. Proposed topics. -1- EPR fundamentals for an isotropic S=1/2 system,
What is EPR? pg Electron Paramagnetic Resonance a.k.a. ESR a.k.a. FMR Electron Spin Resonance Ferro Magnetic Resonance Proposed topics pg 2-1- EPR fundamentals for an isotropic S=1/2 system, -2- anisotropy
More informationSpins and spin-orbit coupling in semiconductors, metals, and nanostructures
B. Halperin Spin lecture 1 Spins and spin-orbit coupling in semiconductors, metals, and nanostructures Behavior of non-equilibrium spin populations. Spin relaxation and spin transport. How does one produce
More informationChapter 7. Nuclear Magnetic Resonance Spectroscopy
Chapter 7 Nuclear Magnetic Resonance Spectroscopy I. Introduction 1924, W. Pauli proposed that certain atomic nuclei have spin and magnetic moment and exposure to magnetic field would lead to energy level
More informationcharges q r p = q 2mc 2mc L (1.4) ptles µ e = g e
APAS 5110. Atomic and Molecular Processes. Fall 2013. 1. Magnetic Moment Classically, the magnetic moment µ of a system of charges q at positions r moving with velocities v is µ = 1 qr v. (1.1) 2c charges
More informationPotential energy, from Coulomb's law. Potential is spherically symmetric. Therefore, solutions must have form
Lecture 6 Page 1 Atoms L6.P1 Review of hydrogen atom Heavy proton (put at the origin), charge e and much lighter electron, charge -e. Potential energy, from Coulomb's law Potential is spherically symmetric.
More informationLectures on Quantum Gases. Chapter 5. Feshbach resonances. Jook Walraven. Van der Waals Zeeman Institute University of Amsterdam
Lectures on Quantum Gases Chapter 5 Feshbach resonances Jook Walraven Van der Waals Zeeman Institute University of Amsterdam http://.../walraven.pdf 1 Schrödinger equation thus far: fixed potential What
More informationLecture 4: Polyatomic Spectra
Lecture 4: Polyatomic Spectra 1. From diatomic to polyatomic Ammonia molecule A-axis. Classification of polyatomic molecules 3. Rotational spectra of polyatomic molecules N 4. Vibrational bands, vibrational
More informationd 3 r d 3 vf( r, v) = N (2) = CV C = n where n N/V is the total number of molecules per unit volume. Hence e βmv2 /2 d 3 rd 3 v (5)
LECTURE 12 Maxwell Velocity Distribution Suppose we have a dilute gas of molecules, each with mass m. If the gas is dilute enough, we can ignore the interactions between the molecules and the energy will
More informationCHAPTER 6: AN APPLICATION OF PERTURBATION THEORY THE FINE AND HYPERFINE STRUCTURE OF THE HYDROGEN ATOM. (From Cohen-Tannoudji, Chapter XII)
CHAPTER 6: AN APPLICATION OF PERTURBATION THEORY THE FINE AND HYPERFINE STRUCTURE OF THE HYDROGEN ATOM (From Cohen-Tannoudji, Chapter XII) We will now incorporate a weak relativistic effects as perturbation
More informationGoal: find Lorentz-violating corrections to the spectrum of hydrogen including nonminimal effects
Goal: find Lorentz-violating corrections to the spectrum of hydrogen including nonminimal effects Method: Rayleigh-Schrödinger Perturbation Theory Step 1: Find the eigenvectors ψ n and eigenvalues ε n
More informationPHYSICS. Course Syllabus. Section 1: Mathematical Physics. Subject Code: PH. Course Structure. Electromagnetic Theory
PHYSICS Subject Code: PH Course Structure Sections/Units Topics Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Section 7 Section 8 Mathematical Physics Classical Mechanics Electromagnetic
More information