Intermetallic Compound TiM (M=Co, Fe) with a Layered Structure Prepared by Deoxidizing Ilmenite‐type Oxides in Molten LiCl‐CaH2 Mixtures

Abstract

AbstractCsCl‐type intermetallic compounds TiM (M=Co, Fe) were obtained by deoxidizing trigonal ilmenite‐type MTiO3 with a reducing agent CaH2 in molten LiCl at 600 °C. X‐ray diffraction, nitrogen adsorption, scanning electron microscopy, and transmission electron microscopy with energy‐dispersive X‐ray, and X‐ray photoelectron spectroscopy analyses revealed the formation of nanoscale layered structures, which enhanced specific surface areas (approximately 20 m2/g) in the intermetallic compounds. In the initial deoxidation stage, Li2TiO3‐like compounds were observed as an intermediate, suggesting the substitution of M in MTiO3 by Li from the molten LiCl. Compound MTiO3 has a layered structure perpendicular to the c axis of the trigonal structure, suggesting that the layered structures may originate from the crystal structure of the precursors. Formation of the Li2TiO3‐like intermediate may help maintain the original layered structure during deoxidation and the subsequent alloying at temperatures as low as 600 °C.