Correlation between magnetoresistivity and magnetic entropy change in the 3D-Heisenberg ferromagnet CuCr2Te4

We report a correlation between magnetoresistivity [Delta rho(mag) = rho(mag)(H,T) - rho(mag)(0,T)] and magnetic entropy change [Delta S-M = S-M(H,T) - S-M(0,T)] in the metallic spinel CuCr2Te4 which orders ferromagnetically below T-C = 320 K. We find that Delta rho(mag) = K Delta S-M for several temperatures around T-C with a temperature independent K, which suggests that magnetoresistivity arising from the suppression of spin disorder scattering scales with Delta S-M. However, unlike expected theoretically, a clear correlation is not obtained between Delta rho(mag) and square of the reduced magnetization (M/M-sat)(2), where M-sat is saturation magnetization at 0 K. A maximum magnetoresistance of -3.56% for mu(0)Delta H = 5 T and magnetic entropy change of -1.57 J/kg K occur at T-C, which are typical values for itinerant ferromagnets. Critical exponent analysis using modified Arrott plots yield beta = 0.371 +/- 0.005 and gamma = 1.312 +/- 0.02 that are close to the 3D-Heisenberg (beta = 0.365; gamma = 1.336; and delta = 4.66) model. (C) 2013 AIP Publishing LLC.