Multiphase Ho36Co48Al16 alloy featuring table-like magnetocaloric effect

Abstract

Table-like magnetocaloric effect is an important requirement for obtaining high efficiency performance in magnetic refrigeration that uses Ericsson cycle. Magnetic and magnetocaloric properties of Ho36Co48Al16 alloy, carefully selected from multiphase region of the ternary Ho-Co-Al system, have been studied. The multiphasic alloy exhibits three magnetic phase transitions spread over a wide temperature range. Suitable distribution of phase proportions and respective magnetic entropy changes result in the broadening of the overall peak magnetic entropy change of the alloy. Table-like magnetocaloric effect is obtained with magnetic entropy change of 8.5 J/kg K and large refrigerant capacity of 525 J/kg under applied magnetic field change of 0–5 T. At field change of 0–2 T, the magnitude of the magnetic entropy change plateau is 2.9 J/kg K with refrigerant capacity of 180 J/kg. The table-like feature and the competitive refrigerant capacity and applied magnetic field change values make the multiphase alloy a practical magnetic refrigerant for efficient low temperature cooling applications that employ the Ericsson cycle, even under permanent magnets.