Magneto-Mechanical Properties and Magnetocaloric Behaviour of Rapidly Solidified Melt-Spun Ni₅₀Mn₂₈Ga₂₂ Heusler Alloy

Rapidly solidified melt-spun ribbons of Ni₅₀Mn₂₈Ga₂₂ Heusler alloy were prepared at two different wheel speeds of 1300 and 1600 RPM and were annealed at different temperatures over different time periods to study the magneto-mechanical properties and magnetocaloric behaviour of the alloy. Annealed ribbons showed higher MFIS (magnetic field induced strain) than as-spun ribbons; ribbon prepared at 1300 RPM and annealed at 900 °C for 5 h (¹³⁰⁰NMG₅ ⁹⁰⁰) showed the highest MFIS value ~1547 με. From the texture analysis, a higher magnetization value at 90° angle of alignment of the sample surface with respect to the field direction indicates that a <110> easy axis might be a possibility. Magnetocaloric behaviour of the ribbons were investigated with the help of SQUID magnetometer. ∆S_m values were calculated from the SQUID data which were further used to calculate the RC (refrigeration capacity) values. The highest RC value was obtained for¹³⁰⁰NMG₅ ⁸⁰⁰; 273 J/kg.