Magnetism and Magneto-resistance of a CrO_2/RuO_2 Granular System

摘要

After mixing RuO_2 and CrO_2 powders, (RuO_2)_x(CrO_2)_(1-x) was sintered at a low temperature of 473 K. The effects of using an RuO_2 spacer between CrO_2 grains were systematically studied for values of x between 0 and 1. The x-dependence of the averaged saturation magnetic moment mu_s per transition metal ion abruptly decreased even at x = 0.03, and it linearly varied in the range 0.3 <= x <= 1, where the estimated magnetic moment per Cr ion was 1.43 mu_B, a 30 percent reduction from the value of 2 mu_B for pure CrO_2 The magneto-resistance ratio (MRR) remained almost unchanged in the range 0 <= x <= 0.7.