Magnetic properties and magnetocaloric effect in the HoNi _1-xCu_xIn (x=0, 0.1, 0.3, 0.4) intermetallic compounds

The magnetic properties and magnetocaloric effect (MCE) in HoNi _1-xCu_xIn (x=0, 0.1, 0.3, 0.4) compounds have been investigated. With the substitution of Cu for Ni, the Ho magnetic moment will cant from the c-axis, and form a complicated magnetic structure. These compounds exhibit two successive magnetic transitions with the increase in temperature. The large reversible magnetocaloric effects have been observed in HoNi _1-xCu_xIn compounds around T_ord, with no thermal and magnetic hysteresis loss. The large reversible isothermal magnetic entropy change (-ΔS_M) is 20.2 J/kg K and the refrigeration capacity (RC) reaches 356.7 J/kg for field changes of 5 T for HoNi_0.7Cu _0.3In. Especially, the value of -ΔS_M (12.5 J/kg K) and the large RC (132 J/kg) are observed for field changes of 2 T for HoNi _0.9Cu_0.1In. Additionally, the values of RC are improved to 149 J/K for the field changes of 2 T due to a wide temperature span for the mix of HoNi_0.9Cu_0.1In and HoNi_0.7Cu _0.3In compounds with the mass ratio of 1:1. These compounds with excellent MCE are expected to have effective applications in magnetic refrigeration around 20 K.