LOW FIELD MAGNETOCONDUCTIVITY IN THIN-CRYSTALS

Low field magnetoconductivity measurements have been performed on thin crystals of Bi2(Te1-xSx)3. Δσ(B) > 0 when σ < σmin and Δσ(B) < 0 when σ > σmin, the minimum metallic conductivity. Δσ(B) vs B/(T-Tc) curves are superimposed for different temperatures; Tc < 0. At high source-drain fields E Δσ(B) vs B/ (T-Tc + aE) curves are approximately superimposed for different fields; a is a positive coefficient. For very low conductivity samples, however, Δσ(B) increases with increasing E. At temperatures T < 3 °K a reverse hysteresis" is observed-when scanning across B = 0 σ(rmB) reaches its maximum (or minimum) before B = 0. © 1979."