Room-temperature magnetic refrigerator using permanent magnets

A magnetic refrigerator device based on adiabatic magnetic refrigeration is described. The magnetic material is cyclically magnetized and demagnetized by permanent magnets in an adiabatic process. A temperature difference of 1.6 Ii between the hot and cold regions was obtained under a low: magnetic field (0.3 T). Gadolinium was the magnetic material used in experiments at room temperature. The range of working temperatures is between 70 and 300 K for a variety of active magnetic materials. The optimized experimental set up increased the device efficiency by achieving a temperature difference be tween hot and cold sources up to 5 K.