Electromagnetism and thermostability of Cr7C3synthesised with high-temperature and high-pressure quenching method.

Abstract

The interactions between the carbon skeleton and metal atoms in binary transition metal carbides are of particular interest for industrial applications involving advanced physics and chemistry, especially in magnetoelectric functional materials and cemented carbides. Cr and carbon BTMCs are a series of intermetallic compounds with specific chemical formulas that share certain unique characteristics. In this study, we used polycrystalline powders of chromium and carbon as precursors and synthesised single-phase bulk Cr₇C₃(orthorhombic, space group:Pnma) with high density and good crystallinity using a high-temperature and high-pressure quenching method (HTHPQM). We studied the material properties and electronic structures of Cr₇C₃with both experimental measurements and density functional theoryab intiosimulations and found that Cr₇C₃is a conductor with an electrical conductivity (2.32 × 10^-3Ω m), relatively high compaction (97.2%), excellent thermostability (oxidation at 1175 K), and a magnetic phase transition from paramagnetism to soft ferromagnetism around 50 K, and the electromagnetic properties are chiefly due to the abundance of the 3delectrons of Cr, and the orbital hybridisation between C and Cr with their 2pand 3delectrons is the reason for the crystal structure and high thermostability. Therefore, the synthesised Cr₇C₃is a multifunctional material with promising application prospects, and HPHTQM is a simple and effective method for preparing samples.