On the nature of the (de)coupling of the magnetostructural transition in Er₅ Si₄

Abstract

In this report, a successful thermodynamical model was employed to understand the structural transition in Er5Si4, able to explain the decoupling of the magnetic and structural transition. This was achieved by DFT calculations, which were used to determine the energy differences at 0 K, using a LSDA+U approximation. It was found that the M structure is the stable phase at low temperatures, as verified experimentally with a value of ΔF0= -0.262 eV. Finally, a variation of Seebeck coefficient (~6 µV) was determined at the structural transition, which allows to conclude that the electronic entropy variation is negligible in the transition.

Lanthanum Dilution Effects on the Giant Magnetocaloric Gd5Si1.8Ge2.2 Compound

“…It is patent that in this family of compounds, atomic structure plays a vital role of the magnetic properties and is responsible for their exotic features. There is a vast number of studies reporting the properties of this pseudo‐binary family by combining different R elements and Si:Ge ratio . For heavy rare earth elements, the system crystallizes in three different crystal structures: orthorhombic O(I) (Gd 5 Si 4 ‐type), orthorhombic O(II) (Sm 5 Ge 4 ‐type), and M (Gd 5 Si 2 Ge 2 ‐type) .…”