Structural ,transport and magnetic properties of double exchange (Fe1-x Mnx)75P15C10 amorphous ferromagnetic alloys

Abstract

(Fe1-xMnx)75P15C10 (x=0.0, 0.10, 0.20 and 0.30) alloys have been prepared in the form of ribbon by standard melt-spinning technique in air with wheel speed of 25 m/sec and cooling rate 1.8x106 K/sec. The prepared samples have been characterized by the structural, transport and magnetic properties measurements. The structural property of the alloys is confirmed by an X-ray diffraction experiment. X-ray diffraction patterns confirm the amorphous nature of the samples. The transport property is carried out at room temperature and the temperature range (93-298)K. Room temperature resistivity increases with the increase of Mn in the system. The magnetic impurities, scattering and topological spin disorder are thought to be responsible for the increase of resistivity of the samples. Normalized resistivity increases slightly with decrease in temperature for samples x=0.10 and x=0.20 and decreases with the decrease in temperature for samples x=0.00, 0.30. But for x=0.30, normalized resistivity gradually decreases upto 137K afterwards the resistivity increases with the decrease in temperature. This behavior is assumed to have been originated from the structural and topological scattering contribution. The magnetoresistance of the samples varied from 0 to 6% upto 0.57T applied magnetic field. Room temperature Hall resistivity measurement shows that the anomalous Hall effect which is attributed to the anisotropic spin scattering centers, magnons and the magnetic impurities. DTA measurement shows that an exothermic peak arises above 690 K for each sample which indicates the onset of crystallization of the grains. TGA measurement shows that mass is slightly gained in all samples. The real permeability decreases with the increase of Mn content and also with the frequency. Imaginary permeability increases linearly with the frequency which means that at higher frequency domains do not follow the applied force. Magnetization measurement shows that saturation magnetization and the average magnetic moment per formula unit of (Fe1-xMnx)75P15C10 decreases with the increase of Mn content.