Introduction to Nanophysics - A

Transcription

1 Introduction to Nanophysics - A Pavlo Mikheenko Department of Physics, University of Oslo, P.O. Box 1048, Blindern, 0316 Oslo, Norway

2 New mechanism of penetration of vortices into current-saturated superconducting Films Yu. M. lvanchenko and P. N. Mikheenko Physicotechnical Institute, Academy of Sciences of the Ukrainian SSR, Donetsk Zh. Eksp. Teor. Fiz. 85, (1983)

3 Internal penetration of vortices into superconducting film MgB 2, width 5 mm thickness 3000 nm T = 3.7 K NbN, width 3 mm, thickness 170 nm

4 Physiological effects of CO 2 at various concentrations by volume 0.03% Nothing happens, it is the normal carbon dioxide concentration in air. 0.5% Lung ventilation increases by 5 percent, maximum safe working level. 1.0% 2.0% 3.0% 5-10% 10-15% Feeling hot and clammy, lack of attention to details, fatigue, anxiety, clumsiness and loss of energy, jelly legs. Lung ventilation increases by 50 percent, headache, loss of energy, feeling rundown. It may take up to several days for the body to return to normal. Lung ventilation increases by 100 percent, panting, headache, dizziness and possible vision disturbance such as speckled stars. Violent panting, fatigue to the point of exhaustion, severe headache, irreversible effects to health. Possible unconsciousness and death. Intolerable panting, severe headaches and rapid exhaustion. Unconsciousness and suffocation without warning. A burning paraffin candle is extinguished. 25% to 30% Coma and convulsions within one minute of exposure. Certain death.

5 Sensor device - timeline Development of columnar growth technique for superconducting materials (YBa 2 Cu 3 O x, GdBa 2 Cu 3 O x ) Applications of columnar growth technique for superconducting coated conductors Extension to functional oxides Extension to conductive transparent superconductors 2010 Invention of device 2010 Experiments with sensor

6 2D self-assembly of nanoparticles Three-dimensional AFM image of Au nanoparticles on STO substrate deposited with 25 laser pulses at 780 C. The height of the pixels is scaled with the planar sizes in the plot.

7 Surface morphology of YBCO film on Ag-decorated MgO substrate SEM image of the surface of YBCO film grown on Audecorated substrate. The inset shows AFM image of the surface of Ag-decorated MgO substrate similar to that on which YBCO film was grown.

8 Cross-sectional AFM images of YBCO Au Ag STO STO YBCO YBCO YBCO columns in an Au-decorated sample. The diameter of the columns is larger than in the films on Ag-decorated substrates on the right. Cross-sectional AFM images of a cleaved YBCO film on STO substrate decorated with Ag nanoparticles. The vertical YBCO columns of a diameter of about 20 nm are seen in the film.

9 Columnar structure of YBCO on 2D array of nanoparticles TEM image of a cross-sectional area inside YBCO film grown on substrate decorated with Ag nano-particles. A regular nanometerscale columnar structure is seen in the image.

10 Surface morphology of YBCO film on Ag-decorated MgO substrate SEM image of the etched YBCO film shown in previous slide. The etching took place along the extended defects in the film and the detached in the areas close to the pores YBCO nanocolumns are seen spread along the surface of the film.

11 Published papers on columnar growth technique in superconducting materials 1. P. Mikheenko, V-S. Dang, A. Sarkar, J. S. Abell and A. Crisan, Integrated pinning centers in YBa 2 Cu 3 O x thick films on single-crystalline and textured metal substrates, Journal of Physics: Conference Series (2011). 2. P. Mikheenko, V-S Dang, Y Y Tse, M M Awang Kechik, P Paturi, H Huhtinen, Y Wang, A Sarkar, J S Abell and A Crisan, Integrated nanotechnology of pinning centers in YBa 2 Cu 3 O x films, Supercond. Sci. Technol (2010) doi: / /23/12/ P. Mikheenko, J. S. Abell, A. Sarkar, V-S. Dang, M.M. Awang Kechik, J.L. Tanner, P. Paturi, H. Huhtinen, N. Hari Babu, D. A. Cardwell, and A. Crisan, Nano techniques for enhancing critical current in superconducting YBCO films, J. Supercond. Nov. Magn., DOI: /s (2010). 4. P. Mikheenko, J. S. Abell, A. Sarkar, V.S. Dang, M.M. Awang Kechik, J.L. Tanner, P. Paturi, H. Huhtinen, N. Hari Babu, D. A. Cardwell, and A. Crisan, Self-assembled artificial pinning centers in thick YBCO superconducting films, Journal of Physics: Conference Series doi: / /234/2/ (2010) 5. P. Mikheenko, J.L. Tanner, J. Bowen, A. Sarkar, V.-S. Dang, J.S. Abell and A. Crisan, Nanodots induced columnar growth of YBa 2 Cu 3 O x films, Physica C, 470 S234-S236 (2010).

12 Semiconducting sensor device: structure

13 Semiconducting sensor device: structure

14 CO 2 sensor device

15 CO 2 sensor device: experimental set-up

16 CO 2 sensor device: experiment

17 CO 2 sensor device: erasing signal

18 R (Ohm) CO 2 sensor device: experiment 6000 T = 296 K Flame is off Cover is open 3000 Flame is off LIGHT IS ON t (s)

19 R (Ohm) CO 2 sensor device: reproducibility T = 296 K Cover is open LIGHT t (s)

20 R/R 0 (arb. units) CO 2 sensor device: calibration CO 2 (%)

21 Sensor device: main features and applications Specific deposition technique that uses several know-how s Unique approach based on large number (~10,000,000,000) of identical columns Cheap and simple device that can easily be adapted for mobile phones Express monitoring for health applications including personal check of CO 2 level in exhaled air, level CO 2 in premises, environment, car exhausts etc. Can substitute conventional fire detectors Versatile device: by varying additions to the deposited material can be made sensitive to specific gases. Sets of films could be sold

22 Penetration of magnetic flux in YBCO/PrBCO superlattices YBa 2 Cu 3 O x / PrBa 2 Cu 3 O x, width 5 mm thickness ~2000 nm

23 YBCO/PrBCO superlattices: resonances due to interaction with indicator film YBa 2 Cu 3 O x / PrBa 2 Cu 3 O x, width 5 mm thickness ~2000 nm

24 Surface SEM image of YBCO/PrBCO superlattice YBa 2 Cu 3 O x / PrBa 2 Cu 3 O x, thickness ~2000 nm By Thomas Qureishy

25 A bacterial cell: the Nanofactory Pd(0) H nm Pd(II) H 2 2H + + 2e - Hydrogenase Pd(II) + 2e- Pd(0)

26 Schematic representation of hidrogenase action Site of initial Pd +2 reduction e - Electron acceptor site e H e - e + H H + Proton channel H 2 H2 H 2 Hydrogen channel

27 m (10-4 emu) Bio-Pd nanocrystals Pd AprimeClH K H (Oe) H (Oe) X-ray diffraction: average size of nanocrystals nm

28 m(10-4 emu) m (10-4 emu) Bio-Pd nanocrystals em -4 u) M -15 ( AprimeClH H (Oe) H (Oe) Pd crystals in the Bio-Pd powder with large ferromagnetic component Pd crystals in the Bio- Pd powder with small ferromagnetic component

29 Characterisation HRTEM (Bio-Pd D. desulfuricans 5%) Fast Fourier transformation + analysis of reflexes Particles have fcc crystal structure. Values for the (111) and (200) planes and angles show distortion of up to 10% compared to the theoretical values for bulk palladium. Analysed particles are probably icosahedral. HRTEM courtesy of Yu Chen, Nanoscale Physics Research Laboratory, University of Birmingham FFT and analysis courtesy of J. Thomas, Leibniz Institute for Solid State and Materials Research, Dresden

30 Bio-Pd nanocrystals: XMSD

31 Bio-Pd nanocrystals: muon scattering

32 Bio-Pd nanocrystals: muon scattering

33 Home activity for Wed. 18 January and later a) Use internet, find an example of recent mesoscopic device or nanoapplications that seem interesting for you or give an example from your current activity. Explain what mesoscopic conditions, as on page 23 in Thomas Heinzel s book Mesoscopic Electronics in Solid State Nanostructures, Second Edition, 2007 (TH) (page in pdf) or different mesoscopic condition, it satisfies. Prepare couple of ppt or pdf slides to illustrate this. Home activity for Wed. 25 January a) Read: TH, Ch 1 (pp 20-33) and Ch 5 (pp ) (pages in pdf), try to understand it, collect problems in understanding to discuss them together on Practical. b) Do Exercises E5.1 and E5.2 in TH, Ch 5 (p 165). It would be good if you could explain them in detail to other students and lecturer. Introduction 33