Transverse Nernst-Ettingshausen coefficients of tin doped bismuth single crystals

The results of investigations of Bi- single crystal transverse Nernst-Ettingshausen coefficient in the temperature range 80-300 K are presented. Single crystals of Bi/sub 1-x/ , 0/spl les/x/spl les/10.4 at.%, were grown by horizontal zoned recrystallization method. Measurements of Q/sub ijk/ were carried out in the temperature range 80-280 K in a weak magnetic field (uB/spl Lt/1, B<0.1 T). Transverse Nernst-Ettingshausen coefficients Q/sub ijk/ consist of negative electron and hole partial parts and a positive missing (ambipolar electron-hole) part. These parts are anisotropic and have comparable values. For bismuth single crystals at T=80 K Q/sub 312/=0.6*10/sup -3/ m/sup 2//Ks, Q/sub 132/=0.45*10/sup -3/ m2/K/spl middot/s. Acceptor tin doping of bismuth single crystals increase ambipolar part of coefficients Q/sub ijk/ by several times. The coefficients Q/sub 312/ and Q/sub 132/ get up positive maximum value at tin concentrations and temperatures, approximate such that thermoelectric power takes the null value. The investigation discovered an essential influence of internal and recombination charge carrier scattering on the value, sign, temperature and tin-doping dependence of Q/sub 312/ and Q/sub 132/. The increase of tin doped bismuth thermomagnetic coefficients is important for Ettingshausen galvanomagnetic cooling application.