The giant magnetocaloric effect Gd5Si2Ge2 alloy was prepared with 99wt% low purity commercial Gd. Pow-der XRD and magnetic measurements showed that the Gd5Si2Ge2 alloy annealed at 1200℃ for 1 h had a significant magn...The giant magnetocaloric effect Gd5Si2Ge2 alloy was prepared with 99wt% low purity commercial Gd. Pow-der XRD and magnetic measurements showed that the Gd5Si2Ge2 alloy annealed at 1200℃ for 1 h had a significant magnetic- crystallographic first order phase transition at about 270 K. The maximal magnetic entropy change is 17.55 J·kg?1·K?1 under a magnetic field change of 0―5 T. The distinct increase of magnetic entropy change belongs to the first-order phase transition from the orthorhombic Gd5Si4-type to the monoclinic Gd5Si2Ge2-type after high temperature heat-treatment.展开更多
基金This work was supported by the National High Technology Research and Development Program of China(No.2002AA324010).
文摘The giant magnetocaloric effect Gd5Si2Ge2 alloy was prepared with 99wt% low purity commercial Gd. Pow-der XRD and magnetic measurements showed that the Gd5Si2Ge2 alloy annealed at 1200℃ for 1 h had a significant magnetic- crystallographic first order phase transition at about 270 K. The maximal magnetic entropy change is 17.55 J·kg?1·K?1 under a magnetic field change of 0―5 T. The distinct increase of magnetic entropy change belongs to the first-order phase transition from the orthorhombic Gd5Si4-type to the monoclinic Gd5Si2Ge2-type after high temperature heat-treatment.
