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 and thermopower of NbSe3 for T < 40 K. Below a critical strain e(c) approximate 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 with 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 increases and the plateau vanishes near T = 40 K. This. behavior is similar to the magnetoresistance and magnetothermopower reported by Coleman et al., Hundley et al. and Lin et al. respectively. By comparing the magnetic, pressure, and elastic strain effects, we suggest that elastic strain leads to a depletion of an electron pocket at the Fermi surface.