Magneto-thermoelectricproperties of bismuth quantum wires at elastic stretch


D.Gitsu1, T. Huber3, L. Konopko1, A. Nikolaeva1,2


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.