Temperature dependencies ofthe Seebeck coefficients under electric field effect conditions in thin Bi andBi-alloys wires


D.V. Gitsu1, L. A.Konopko1, 2, A.A. Nikolaeva1, 2


1Instituteof Applied Physics, Academy Sciences of Moldova, Academy str. 5, Chisinau,MD-2028, Moldova

2InternationalLaboratory of High Magnetic Fields and Low Temperatures, Wroclav, Poland


The temperaturedependencies (4.2 – 300 K) of Seebeck effect of  thin Bi and Bi-alloys wires in presence of strong (up to 107V/cm) transverse electric field were investigated. The cylindrical Bi andBi-alloys crystals ranging in size from 0.1 to 3 mm with glasscoating were fabricated by Ulitovsky method.  All the samples were similarly oriented: the cylinder axismade an angle of 19.5o with the bisectrix axis in thebisector-trigonal plane. Theoretical calculations predict that electrical fieldeffect (EFE) on thin (100) Bi films considerably enhances the figure of meritM. Moreover nanowires of the semimetal bismuth should have an enhancedthermoelectric figure of merit.

According to ourexperimental data the Seebeck coefficient  increase withECE very slowly and have the opposite dependence from the sign of appliedelectric field than  theoreticalprediction.

Probablemechanisms of the observed effects are discussed.

Thiswork is supported by Civilian Research and Development Foundation for theIndependent States of the Former Soviet Union (CRDF) # MP2 – 3019.