Effect of alloying elements (Zr, Hf, Co), heat and mechanical treatment conditions on the phase composition and magnetic properties of SmFe₁₁Ti compounds with ThMn₁₂ structure

¹ Ural Federal University, Ekaterinburg, Russia
² M.N. Mikheev Institute of Metal Physics of Ural Division of RAS, Ekaterinburg, Russia
³ POZ - Progress Co, Verkhnaya Pushma, Sverdlovsk region, Russia

^* Corresponding author: andrej707@bk.ru

Published online: 4 July 2018

Abstract

The results of thermomagnetic, metallographic and X-ray diffraction phase analysis as well as the measurements of specific magnetization (σ_s), Curie temperature (T_C), coercive force (H_C) of (Sm,M)(Fe,M)_12-xTi_x alloys samples, where M = Zr, Hf, Co with the ThMn₁₂ main phase structure (1-12) are presented. The effect of the annealing temperature and the cooling rate on the formation of 1-12 phase and its magnetic properties, including the effect of high-energy milling on the magnetic hysteresis properties and alloys structure are described. It was found that the highest magnetic characteristics such as σ_s = 112.6 emu/g and T_C = 600 ºC are attained in the (Sm_0.8Zr_0.2)(Fe_0.75Co_0.25)_11.4Ti_0.6 alloy after its annealing at 1050 °C and rapid cooling. It is noted that a mechanical milling of the alloy leads to 1-12 phase amorphization which accompanied by an α-(Fe) or metal Co phases impurity formation.