Critical Behavior of Ferromagnetic Transition in SnO2-Based Diluted Magnetic Semiconductor

Isothermal magnetization data in the critical region of the ferromagnetic transition for Co-doped SnO2-based diluted magnetic semiconductor were measured and analyzed in terms of the modified Arrott plot method and, independently by the Kouvel-Fisher method. The critical exponents beta,gamma, and delta, corresponding to spontaneous magnetization, initial susceptibility and isothermal magnetization, respectively, were determined and the values are found to be comparable to the mean-field model. The critical exponent values are found to be consistent with the Widom scaling relation and the universal scaling hypothesis. The temperature variation of the effective critical exponent is found to show the characteristic behavior of a disordered system.