The studies of phase relation, microstructure, magnetic transition, magnetocaloric effect in (Gd1−xErx)5Si1.7Ge2.3 compounds

► Er as the substitution element for Gd in Gd5Si1.7Ge2.3 compounds. ► The as-cast (Gd1−xErx)5Si1.7Ge2.3 compounds are annealed at 1523 K for 3 h. ► Er can substitutes Gd of Gd5Si2Ge2-type main phases in annealed (Gd1−xErx)5Si1.7Ge2.3 compounds. ► Increasing Er content will decrease magnetic transition temperature (TC), the maximum magnetic entropy change, and magnetic hysteresis, respectively.