Critical behavior of double perovskite La2NiMnO6

The critical behavior of the double perovskite La2NiMnO6 was investigated by measurement of the magnetization around the Curie temperature T-C. The magnetic data were analyzed in the critical region using the Kouvel-Fisher method to yield the critical exponents of beta = 0.408 +/- 0.011 with T-C = 270.50 (from the temperature dependence of the spontaneous magnetization below T-C) and gamma = 1.295 +/- 0.015 with T-C = 271.10 (from the temperature dependence of the inverse initial susceptibility above TC). The critical magnetization isotherm M(T-C, H) gives delta = 4.139 +/- 0.090. The critical exponents obtained by this method obey the Widom scaling relation delta = 1 + gamma/beta, implying the critical exponents are reliable. The values of critical exponents are close to those predicted by the three-dimensional (3D) Heisenberg model with short-range interactions.