Effect of Dy substitution on magnetic properties and magnetocaloric effects of Tb6Co1.67Si3 compounds

The magnetic and magnetocaloric properties of (Tbmagnetic properties, magnetic entropy change, refrigerantcapacityProject supported by the NationalBasic Research Program of China (Grant No.~2006CB601101), theNational Natural Science Foundation of China (Grant Nos.~50731007and 10874223) and the Knowledge Innovation Project of the ChineseAcademy of Sciences.7530S, 7550CThe magnetic and magnetocaloric properties of (Tbmagnetic properties, magnetic entropy change, refrigerantcapacityProject supported by the NationalBasic Research Program of China (Grant No.~2006CB601101), theNational Natural Science Foundation of China (Grant Nos.~50731007and 10874223) and the Knowledge Innovation Project of the ChineseAcademy of Sciences.7530S, 7550CThe magnetic and magnetocaloric properties of (Tbmagnetic properties, magnetic entropy change, refrigerantcapacityProject supported by the NationalBasic Research Program of China (Grant No.~2006CB601101), theNational Natural Science Foundation of China (Grant Nos.~50731007and 10874223) and the Knowledge Innovation Project of the ChineseAcademy of Sciences.7530S, 7550CThe magnetic and magnetocaloric properties of (Tb$_{1 -x}$Dy$_{x})_{6}$Co$_{1.67}$Si$_{3}$ ($0 le x le 0.8$) have beenexperimentally investigated. The compounds exhibit aCe$_{6}$Ni$_{2}$Si$_{3}$-type hexagonal structure and undergo asecond-order magnetic transition. The Curie temperature decreasesfrom $sim 187$~K to 142~K as the content of Dy grows from 0 to 0.8.The maximal magnetic entropy change, for a field change of 0--5~T,varies between $sim 6.2$ and $sim 7.4$~J/kg$cdot$K, slightlydecreasing when Dy is introduced. The substitution of Dy leads to aremarkable increase in refrigeration capacity (RC). A large RC valueof $sim 626$~J/kg is achieved for $x=0.4$ under a field change of0--5~T.