THE EFFECT OF ELASTIC STRAIN ON THE RESISTANCE ANOMALY AND THE THERMOPOWER OF NBSE3

We have investigated the effect of elastic strain on the resistance an d thermopower of NbSe3 for T < 40 K. Below a critical strain e(c) appr oximate to 0.5 % the piezoresistance DR/R(0) = [R(e) - R(0)]/R(0) and the piezothermopower DS/S(0) = [S(e) - S(0)/S(0) increase linearly wit h strain at a T dependent rate. Above e(1) approximate to 0.50% +/- 0. 10% both exhibit a plateau-like feature up to a temperature dependent strain value e(2)(T). The width of the plateau decreases as T increase s and the plateau vanishes near T = 40 K. This. behavior is similar to the magnetoresistance and magnetothermopower reported by Coleman et a l., Hundley et al. and Lin et al. respectively. By comparing the magne tic, pressure, and elastic strain effects, we suggest that elastic str ain leads to a depletion of an electron pocket at the Fermi surface.