Zhong Xichun

Magnetic properties and magnetic entropy changes of MRE

(La 0.5 Ce 0.5 ) 2 Co 7 and (Ce 0.65 Pr 0.35 ) 2 Co 7 compounds for magnetic refrigeration were studied by X-ray diffraction, ac susceptibility and isothermal magnetization measurements. X-ray powder diffraction shows that all the compounds have hexagonal Ce 2 Ni 7 -type structure . The Curie temperatures ( T C ) are 258 K and 222 K for (La 0.5 Ce 0.5 ) 2 Co 7 and (Ce 0.65 Pr 0.35 ) 2 Co 7 compounds, respectively. High coercivities ( H C ) of about 1.74 and 6.61 kOe at 5 K with a smooth demagnetization curves were obtained for the (La 0.5 Ce 0.5 ) 2 Co 7 and (Ce 0.65 Pr 0.35 ) 2 Co 7 compounds, respectively. For an applied field change from 0 to 50 kOe, the maximum ( - Δ S M ) for (La 0.5 Ce 0.5 ) 2 Co 7 and (Ce 0.65 Pr 0.35 ) 2 Co 7 compounds are 0.52 and 0.67 J/(kg K), respectively.