Magnetometric and Moessbauer studies on magnetic properties of pseudo-ternary compounds Y(Co1-xFex)4B (0 ≤ x ≤ 0.35)

Magnetization measurements as well as Moessbauer spectroscopy have been performed on pseudo-ternary Y(Co1-xFex)4B (0 ≤ x ≤ 0.35) compounds in order to investigate their magnetic properties. Powder samples aligned in a magnetic field at room temperature were used for the magnetization and X-ray diffraction measurements. The spin-reorientation transition, which was a change in the magnetization direction from parallel to the c-axis below a transition temperature Tsr to one perpendicular to the c-axis above Tsr, was observed in very narrow Fe concentration range 0 ≤ x ≤ 0.03. All the compounds above x = 0.05 have a magnetization direction in the c-plane over the whole temperature range below TC. The magnetic x - T phase diagram is determined by these results. The Moessbauer spectra measured for 0.05 ≤ x ≤ 0.35 reveal a strong preferential occupation of Fe for the 2c site. The average Fe moment is nearly constant by 1.04μB below x = 0.1 and increase above x = 0.1 up to 1.17μB at x = 0.35. Averaged Co moment increases monotonously from 0.69μB at x = 0 to 1.15μB at x = 0.35. (orig.)