Tunable magnetocaloric effect in RTi _1−x Mo _x Ge (R = Tb, Er) (x = 0, 0.15) compounds

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 as 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.

The magnetocaloric properties of GdScSi and GdScGe

“…The CeFeSitype forms present magnetocaloric properties associated to a field-induced magnetic phase transition [11]. Concerning the magnetocaloric effect of the CeScSi-type forms only few studies are reported, for instance ErTi 0.85 Mo 0.15 Ge exhibits MCE around 62 K [12]. In this paper, we report on the synthesis of GdScSi and GdScGe and their investigation using X-ray powder and single crystal diffraction and magnetization measurements.…”

Magnetic properties and magnetocaloric effects in antiferromagnetic ErTiSi

“…A similar result was also observed in ErTiGe compound. 18,19 The anomaly at low temperature ͑T AF = ϳ 9 K͒ may be associated with a possible change from collinear to noncollinear AFM structure. 19 The transition at a higher temperature corresponds to a change from AFM to paramagnetic ͑PM͒ state with increasing temperature, and its Néel temperature T N is determined to be 46 K. It is also found from Fig.…”

“…18,19 The anomaly at low temperature ͑T AF = ϳ 9 K͒ may be associated with a possible change from collinear to noncollinear AFM structure. 19 The transition at a higher temperature corresponds to a change from AFM to paramagnetic ͑PM͒ state with increasing temperature, and its Néel temperature T N is determined to be 46 K. It is also found from Fig. 2 that the magnetic susceptibility of the ErTiSi compound at temperatures above ϳ65 K perfectly follows the Curie-Weiss law m −1 = ͑T − p ͒ / C m , where p is the PM Curie temperature and C m is the Curie-Weiss constant.…”

Magnetocaloric effect in rare-earth intermetallics: Recent trends

“…The large changes in magnetization values around the critical field reflect in the temperature dependence of S m and T ad . For example, the Dy 5 Si 2 Ge 2 , DySi and RTiGe compounds show interesting metamagnetic behaviour in their magnetically ordered state [39][40][41]. In particular, the Dy 5 Si 2 Ge 2 compound (orthorhombic, Sm 5 Ge 4 -type) orders antiferromagnetically with T N ∼ 56 K and undergoes metamagnetic transition at temperatures below 40 K. This leads to enhanced magnetocaloric effect with an additional peak feature below T N for field changes above 2 T ( figure 3).…”