Magnetic properties and enhanced magnetic refrigeration in (Mn1−xFex)5Ge3 compounds

Magnetic and magnetocaloric effects of ${\left({\text{Mn}}_{1-x}{\text{Fe}}_x\right)}_5{\text{Ge}}_3$ compounds are studied systematically. The maximum of magnetic entropy changes of 8.01 J/kg K under an external field change of 5 T is obtained for ${\left({\text{Mn}}_{0.9}{\text{Fe}}_{0.1}\right)}_5{\text{Ge}}_3$ , which is the largest value in ${\text{Mn}}_5{\text{Ge}}_3$ -based solid solutions. Moreover, the Fe substitution increases the refrigeration capacity (RC) value greatly. The largest RC value of 237 J/kg in ${\left({\text{Mn}}_{0.8}{\text{Fe}}_{0.2}\right)}_5{\text{Ge}}_3$ even compares favorably to that of many well-known magnetic refrigeration materials. Thus the Fe-containing ${\left({\text{Mn}}_{1-x}{\text{Fe}}_x\right)}_5{\text{Ge}}_3$ compounds are much-improved magnetic refrigerants for the application of room-temperature magnetic refrigeration. The increase of the RC value is probably resulted from the formation of magnetic nanostructure.