Effect of B alloying on magnetocaloric effect of Gd5.1Si2Ge2 alloy in low magnetic field

A series of the Gd5.1Si2Ge2-xBx alloys were prepared with arc melting in purified argon atmosphere. The effect of B addition on the magnetocaloric effect of compound Gd5Si2Ge2 was investigated by powder X-ray diffraction technology and DSC and direct magnetocaloric effect apparatus and vibrating sample magnetometer (VSM). The results show that the addition of a small amount of B maintains the Gd5Si2Ge2 compound in single monoclinic phase with superior magnetocaloric effect, especially when x=0.01, the maximum magnetic entropy change (vertical bar Delta S-M vertical bar) reaches the values of 13.7 J/(kg.K) at 288 K in 1.5 T magnetic field. With the increase of B content, some orthorhombic Gd5Si4-type phases appear in the matrix of monoclinic Gd5Si2Ge2-type phase in Gd5.1Si2,Ge2-xBx alloys.