Magnetic and magnetocaloric properties in GdZn_(2) synthesized by ball milling

摘要

In this study,we prepared GdZn_(2)by mechanical alloying method and measured its magnetization to reveal the magnetic and magnetocaloric properties.For a milling time(MT)≥10 and 20 h,the GdZn_(2)phase was confirmed by X-ray diffraction measurements.For MT=40 and 60 h,amorphous like patterns are observed.For MT=10 and 20 h,magnetization(M)as a function of temperature below 80 K shows ferromagnetic-like increase.The observed values of M are 4.5μ_(B) at 5 K for MT=10 and 20 h,which is smaller than that of the theoretical expected value of 7μ_(B).For MT=40 and 60 h,the long-range ferromagnetic order collapses because there is no spontaneous magnetization.The value ofΔT,whereΔT is the full width at half maximum of the magnetic entropy change(ΔS_(m)(T)),increases significantly for MT≤20 h because of the gradual release of magnetic entropy by the milling effect.Since M decreases with increasing MT,the maximum values of|ΔS_(m)|,the relative cooling power,and the refrigerant capacity also decreases.