Gas-phase interstitially modified intermetallics R(Fe₁₁Ti)Z_{1- delta}. I. Magnetic properties of the series R(Fe₁₁Ti)C_{1- delta}: R=Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Lu

Abstract

A series of tetragonal rare-earth-iron intermetallic carbides R(Fe11Ti)C1- delta of rare-earths from Nd to Lu have been prepared by reaction of intermetallic powders with butane (C4H10) at temperatures between 480 degrees C and 520 degrees C. On average, the unit cell volume increases upon carbonation by 1.8% across the series. Curie temperatures increase by about 160 K. Values of magnetization at room temperature and 4.2 K are reported. All compounds were found to have easy-axis anisotropy at room temperature, with the exception of Sm which is easy plane. Magnetization curves of aligned samples of the solid solution series (Y1-xNdx)(Fe11Ti)C1- delta give an anisotropy field for the Nd(Fe11Ti)C1- delta compound of 17(2) T at 4.2 K, and 6(1) T at room temperature. Structural effects of interstitial modification of the intermetallic compounds are discussed, as are the possibilities of introducing interstitial atoms other than H, C and N into these types of alloys via gas-phase reactions.