Phase equilibria and magnetic phases in the Fe-rich regions of the Ce-Fe-{Ni, Si, Al}-B quaternary systems

Fe-rich regions of the Ce-Fe-{Ni, Si, Al}-B quaternary systems were experimentally studied using diffusion couples and selected key alloys. After sufficient annealing of at least 10 days at 900 °C, samples were quenched in a cold water bath. Homogeneity ranges of Ce2(Fe14-xNix)B, Ce2(Fe14-xSix)B and Ce2(Fe14-xAlx)B solid solutions were measured to be (0 ≤ xNi ≤ 1.5), (0 ≤ xSi ≤ 2.33) and (0 ≤ xAl ≤ 2.5), respectively. Quaternary solid solutions Ce(Ni4-xFex)B (0 ≤ x ≤ 0.78) and (Fe1-x-yNixCey)23B6 (0 ≤ y ≤ 0.062, x = 0.832) were also found in the Ce-Fe-Ni-B quaternary system. Except (Fe1-x-yNixCey)23B6, (Fe1-x-ySixCey)23B6 and (Fe1-x-ySixCey)3B, all other quaternary solid solutions observed are in equilibrium with α-Fe. Magnetic force microscopy was used to screen magnetic phases. Among the phases observed in the Fe-rich regions of the Ce-Fe-{Ni, Si, Al}-B quaternary systems, only the quaternary extensions of Ce2Fe14B show visible magnetic domains.