Investigation of magnetic and electrical properties in the Mo-substituted Ni-Mn-Sb Heusler alloys

In this study, Heusler alloys with nominal composition of Ni50-xMoxMn37Sb13+B2 (x = 0, 1, 3, 5, and 7) were synthesized by the arc-melting method. In the samples with low Mo-content, 4O and 10 M phases were obtained, indicating the presence of the martensite phase, while in the samples with high Mo-content, the L21 phase was determined, which is attributed to the austenite structure. The samples showed a two-step transition between T1 and T2 temperatures in the temperature dependent magnetization measurements, which is attributed to a premartensitic transformation. It was observed that the interval T1-T2 decreased with the increase of Mo-content in the system. It was found that there was an increase in magnetization value due to Curie transition around 350 K in x = 0 and x = 1 Mo-substituted samples, but there was no such increase between 5 and 360 K for other samples. It was found that the blocking temperature (TB) was affected by the Mo-substitution. The thermal hysteresis between the M-T curves during cooling and heating indicates a first-order phase transition in the samples. It is evident from both the M-T and rho-T analyses that the MT temperatures shifted to low temperatures as the Mo-content increases. An exchange bias effect was observed in the samples. increment SM with a positive sign was determined for all samples, reaching a maximum value around MT temperature. The maximum increment SM was obtained at a magnetic field of 5 T at 255 K in the x = 3 Mo-substituted sample. Similarly, the highest RC, AHL and RCeff values were also found for the x = 3 Mo-substituted sample.

Automated summary

In this study, Heusler alloys with different Mo content were synthesized, and their magnetic and phase transition behaviors were investigated by magnetization measurements. It was found that increasing Mo content reduces the T1-T2 temperature interval and affects the blocking temperature. In addition, Mo substitution also significantly influences the magnetization values of the samples, reaching maximum values at specific magnetic fields and temperatures.