The effect of adding aluminum and iron to Tb–Dy–Ho–Co multicomponent alloys on their structure and magnetic and magnetocaloric properties

A comprehensive analysis of the structure, phase composition, surface topology features, and magnetic and magnetocaloric properties of Tb$_{0.3}$Dy$_{0.35}$Ho$_{0.35}$Co$_{1.75}$T$_{0.25}$ ($T$ = Al, Fe) multicomponent alloys has been performed. The specifics of variations in the structure and functional properties induced by the partial substitution of cobalt atoms in the 3d sublattice of RCo$_2$ with aluminum or iron atoms have been determined.