Magnetization and Magnetostriction of LaFe<sub>11.2 – <i>х</i></sub>Mn<sub><i>x</i></sub>Co<sub>0.7</sub>Si<sub>1.1</sub> (<i>x</i> = 0.1, 0.2, 0.3) Alloys In Pulsed Magnetic Fields

Abstract

Abstract—The magnetization and magnetostriction of polycrystalline alloys LaFe11.2 – хMnxCo0.7Si1.1 (x = = 0.1, 0.2, 0.3) were measured in pulsed magnetic fields up to 180 kOe in the temperature range 80–270 K. The replacement of Fe atoms by Mn atoms shifts the TC towards low temperatures and does not affect the value of saturation magnetization. The observed field dependence of the magnetization M(H) near the TC is characteristic of second-order phase transitions, while the temperature dependence of the magnetization M(T) above the TC in strong magnetic fields indicates a first-order magnetic phase transition. The magnetic volume effect ΔV/V reaches 0.81% in a field of 180 kOe. The asymmetry of magnetostriction relative to the temperature of the maximum effect, manifested in strong magnetic fields, and the magnetic field hysteresis of magnetostriction bear signs of a first-order phase transition