Magnetic and magnetocaloric properties in GdZn2 synthesized by ball milling

Abstract

In this study, we prepared GdZn2 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 GdZn2 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 4.5 μB at 5 K for MT = 10 and 20 h, which is smaller than that of the theoretical expected value of 7 μB. For MT = 40 and 60 h, the long-range ferromagnetic order collapses because there is no spontaneous magnetization. The value of ΔT, where ΔT is the full width at half maximum of the magnetic entropy change (ΔSm (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 |ΔSm|, the relative cooling power, and the refrigerant capacity also decreases.