Structure and magnetic properties of ErFe_11-xGa_xTi

Abstract

ErFe11-xGaxTi compounds with ThMn12-type structure were synthesized for x = 0, 1, 2, 3, 4, 5. The crystalline structure and Ga occupancy in the compounds were analysed in terms of the Rietveld method. With increasing Ga content, the lattice constant and unit-cell volume increase monotonically. Ti atoms are found to occupy 8i sites for all the compounds. Bond length and Ga occupancy factor are given. The Curie temperature increases first, going through a maximum and then decreases with increasing x while saturation magnetization decreases monotonically. Spin re-orientation from the uniaxial to the easy-cone type is detected for all the compounds as the temperature decreases from 300 to 5 K. A tentative spin phase diagram is constructed for the ErFe11-xGaxTi. In the ErFe11-xGaxTi compounds, a magneto-history effect is observed which can be attributed to irreversible movement of narrow domain walls that are easily pinned.

Spin reorientation and crystal-field interaction inTbFe12−xTixsingle crystals

“…Some authors assign T sr to the inflection point ͑i.e., a minimum of dЈ/dT), 9,19,20 while other authors place T sr at the Ј vs T maximum. 7,21,22 Here we have adopted the latest definition. Therefore T sr for TbFe 10.7 Ti 1.3 is determined to be 205 K ͑Ϯ5 K͒.…”