The TiNiSi-to-Ni2In-type magnetostructural transitions in alloys with largely reduced Ge-concentrations

•The TiNiSi-to-Ni2In-type magnetostructural transitions in alloys with largely reduced Ge-concentrations.•Tunable magnetostructural transitions in a wide temperature region.•Large magnetic entropy changes under relatively low fields.

The MnNiGe-based and MnCoGe-based intermetallic compounds usually exhibit giant magnetocaloric effects at the TiNiSi-to-Ni2In-type magnetostructural transitions. However, the high concentrations of costly Ge element give rise to relatively high raw-material costs for these alloys. In this work, we realized the TiNiSi-to-Ni2In-type magnetostructural transitions in Mn16Fe16Ni34Si34−xGex system which possesses largely reduced Ge-concentrations. Large magnetic entropy changes were observed under relatively low field in a wide temperature range including room temperature.