Isothermal section at 950 °C of the U–Fe–B ternary system

A systematic investigation of the isothermal section at 950 °C of the U–Fe–B ternary system was done by means of X-ray powder diffraction, scanning electron microscopy, complemented by energy dispersive X-ray spectroscopy, and electron-probe microanalysis. At this temperature the phase diagram is characterized by the formation of four ternary compounds with negligible homogeneity regions. The compounds are: UFeB ₄ (orthorhombic YCrB ₄-type structure, a = 5.887(1) Å, b = 11.412(2) Å and c = 3.4355(4) Å), UFe ₃B ₂ (hexagonal CeCo ₃B ₂-type structure, a = 5.049(1) Å and c = 2.9996(7) Å), ∼UFe ₄B (structure closely related with the CeCo ₄ B-type, and a small hexagonal cell a = 4.932(1) Å and c = 7.037(2) Å), and U ₂Fe ₂₁B ₆ (Cr ₂₃C ₆-type structure, a = 10.766(4) Å).