Current-induced magnetoresistance avalanche in Nd0.5Ca0.5Mn0.95Ni0.05O3

We show that magnetic field (H)(H) dependence of resistivity (ρ)(ρ) in Nd0.5Ca0.5Mn0.95Ni0.05O3 shows unusual features with increasing amplitude of the dc current (I)(I) in the sample. While ρ(H)ρ(H) at T=40K decreases smoothly with increasing HH and exhibits irreversibility with field cycling for current amplitudes less than 1 mA, an avalanche like decrease occurs at a critical value of HH for I>5I>5 mA. The critical field increases with increasing amplitude of the dc current and the ρ(H)ρ(H) exhibits a reversible hysteresis in the complete field cycle at higher dc current strengths. It is shown that the avalanche in ρρ is accompanied by an abrupt decrease in the temperature of the sample (ΔT=47K) which underscores the importance of magnetothermal coupling in the current-induced magnetoresistance avalanche.