Critical behavior and magnetocaloric effect near room temperature in MnCo1-xTixGe alloys

In this paper, we investigate the critical behavior and the magnetocaloric effect of the polycrystalline MnCo1-xTixGe samples with x = 0.02, 0.04, 0.06 and 0.08. For such materials, we show that the maximum entropy change S-M depends on applied magnetic field H-2/3. In order to present a detailed study on the critical behaviors, various techniques such as modified Arrott plot, Kouvel-Fisher method, and critical isotherm analysis are used to determine the critical exponent beta, gamma and delta. The exponents calculated from the critical magnetization isotherm are found to obey the Widom scaling relation remarkably well. Moreover, we also report the accuracy of the three methods using the so-called relative slopes (RS) approach. These critical exponents are found similarly to the theoretical values of the mean-field model, consistent with the existence of long-range ferromagnetic interactions. Suitable magnetocaloric effect and good tunable T-c responses are good candidates for magnetic refrigeration materials room temperature.