Tuning the Competing magnetic interactions in RTiGe (R = Tb, Er) Compounds and tailoring the Magnetocaloric effect

TL;DR

This study demonstrates how substituting Mo for Ti in RTiGe compounds (R=Tb, Er) alters magnetic interactions, switching from antiferromagnetic to ferromagnetic, and significantly enhances their magnetocaloric effect, showing tunability via chemical substitution.

Contribution

It introduces a method to tune magnetic interactions and improve magnetocaloric properties in layered RTiGe compounds through Mo substitution.

Findings

Mo substitution induces ferromagnetic ground state

Enhanced magnetocaloric effect observed in substituted compounds

Magnetic entropy change increases significantly with substitution

Abstract

The tetragonal layered compounds TbTiGe and ErTiGe order antiferromagnetically at 276 K and 39 K, respectively. Partial substitution of Mo for Ti in these two compounds modifies the magnetic interactions giving rise to a ferromagnetic ground state which results in an enhanced magnetocaloric effect. The magnetic entropy change in ErTi0.85Mo0.15Ge for a magnetic field change of 5 T is ~10.5 J/kg/K against ~0.8 J/kg/K for ErTiGe in the vicinity of the magnetic transition. Thus, magnetocaloric properties of such layered materials may be tunable by suitable chemical substitutions.