Abstract
Magnetic refrigeration is expected to be a future technology because of its energy efficiency and environmental safety. The concept of magnetic refrigeration is based on the magnetocaloric effects. In this article, we first review magnetocaloric effects and recent development of magnetic refrigerators. Then, we report the giant magnetocaloric effects of MnAs1-xSbx, which were recently discovered by our group. It is found that a first-order magnetic transition from a ferromagnetic state to a paramagnetic state is responsible for giant magnetocaloric effects in this system. Finally, the prospect of magnetic refrigerant materials at room temperature will be given.
