Magneto-thermoelectricproperties of bismuth quantum wires at elastic stretch

D.Gitsu¹, T. Huber³, L. Konopko¹, A. Nikolaeva^1,2

¹Institute of AppliedPhysics, Academy Sciences of Moldova, Academy str. 5, Chisinau, MD-2028,Moldova

²International Laboratory ofHigh Magnetic Fields and Low Temperatures, Wroclav, Poland

³Department of Chemistry,Howard University, 525 College St. N.W. Washington, DC 20059

Thermoelectric and magnetothermoelectric properties of singlecrystal Bi nanowires obtained by the liquid phase casting by the Ulitovskymethod in a glass cover with diameters from 80nm up to 2 mm were studied. The angular dependences TMR in the magnetic fieldsup to 14T at different temperatures were measured. For the first time theresult in single nanowires with d=80nm was obtained, directly showing thedecrease of overlapping of L- and T- bands due to quantum size effects. Theeffect was registered by the Sh.d.H. oscillations.

Bi wires in a glasscover bear elastic deformations (stretch) up to 2.5-3% relative elongation.

Anisotropicdeformation was used for realization of electron topologic transitions withpurpose to reveal the influence of the Fermi surface topology on the magneto-thermoelectric properties of Bi quantum wires in confinement conditions.

Thermopower andmagnetothermopower depend non-monotonously on stretch and in the temperaturerange 100-50K change sing more than once. Power- factor, its dependence ondiameter, stretch, magnetic field and temperature was calculated. The obtainedresults are discussed from the viewpoint of quantum size effects, inter- bandscattering and actuality of L and T- extremes in the process of stretch andmagnetic quantization.

This work is supported by Civilian Research andDevelopment Foundation for the Independent States of the Former Soviet Union(CRDF) # MP2 – 3019.