Magnetism and transport behavior of Ni42Co8Mn38Sb12: Magnetization, electrical resistivity and Hall effect measurements

Abstract Magnetic and transport behavior of Ni42Co8Mn38Sb12 alloy is discussed using the combined results of magnetization, electrical resistivity and Hall effect measurements. The alloy undergoes a ferromagnetic transition at 364 K, followed by a martensitic transition at 110 K. Large positive Curie-Weiss temperature, soft-ferromagnetic behavior with negative magnetic entropy change below 50 K and a well-scaled normalized magnetic-entropy onto a single universal curve confirm the predominant ferromagnetic exchange interactions in the alloy. Normal Hall coefficients were found to be nearly constant in ferromagnetic region in the temperature range of 120–300 K. The electrical transport properties are largely governed by electrons with a carrier concentration of about 1023/cc. Quadratic dependence of anomalous Hall resistivity (ρxy) on longitudinal resistivity (ρxx ) indicates the dominant intrinsic contribution. In a magnetic field of 50 kOe, magnetoresistance is found to be about 34% near the martensitic transition temperature while it is about 2.8% near the second-order transition.