Stabilization by Si substitution of the pseudobinary compound Gd(2)(Co(3-x)Si(x)) with magnetocaloric properties around room temperature

• Published in: Inorganic chemistry 2014-07, Vol.53 (13), p.6728-6736
• Main Authors: Tencé, Sophie, Caballero Flores, Rafael, Chable, Johann, Gorsse, Stéphane, Chevalier, Bernard, Gaudin, Etienne
• Format: Article
• Language: English
• ISSN: 1520-510X
• DOI: 10.1021/ic500529b

We report the discovery of a new solid solution Gd2(Co3-xSix) with 0.29 < x < 0.50 in the Gd-Co-Si ternary system. Members of this solid solution crystallize with the La2Ni3-type structure and correspond to the stabilization of "Gd2Co3" through silicon substitution. The structure of the member Gd2(Co2.53(3)Si0.47) was determined by X-ray diffraction on a single crystal. It crystallizes with the space group Cmce and cell parameters a = 5.3833(4), b = 9.5535(6), and c = 7.1233(5) Å. Co/Si mixing is observed on two crystallographic positions. All compounds studied in the solid solution present a ferrimagnetic order with a strong composition-dependent Curie temperature TC with 280 K < TC < 338 K. The magnetocaloric effect, which amounts to around 1.7 J K(-1) kg(-1) for ΔH = 2 T, is interestingly tunable around room temperature over a temperature span of 60 K through only 4-5% of composition change.