Zeng Lingmin

The 500°C isothermal section of the phase diagram of the FeGdNd ternary system

Abstract The isothermal section of the phase diagram of the FeGdNd ternary system at 500 °C has been investigated mainly by X-ray powder diffraction, with aid of differential thermal analysis, scanning electron microscope and electron probe microanalysis. The existence of seven binary compounds, namely Fe 2 Gd, Fe 3 Gd, Fe 23 Gd 6 , Fe 17 Gd 2 , Fe 17 Nd 2 , Fe 17 Nd 5 and δ, was confirmed in this isothermal section. The section consists of 9 single-phase regions, 14 two-phase regions and 6 three-phase regions. The maximum solid solubilities of Fe in α-Nd and Nd in Fe 2 Gd, Fe 3 Gd and Fe 23 Gd are about 0.1 at.%, 2.0 at.%, 1.0 at.%, and 2.0 at.% respectively. No ternary compounds were found in this section.

Rietveld Refinement of New Ternary Compound Al14Dy5Si

A new ternary compound Al14Dy5Si was discovered and studied by means of X-ray powder diffraction technique. The ternary compound Al14Dy5Si has a hexagonal BaPb3-type structure, space group R 3 m (No. 166), the lattice parameters a = 0.61482(1) nm, c = 2.09780(2) nm. The crystal structure of the compound Al14Dy5Si was successfully refined by using Rietveld method from X-ray diffraction data. The R-factors of Rietveld refinement are Rp = 0.091 and Rwp = 0.120, respectively. The thermal dependence of the magnetization (M-T curves) for the compound was measured by a vibrating sample magnetometer. The experimentally determined magnetic effective paramagnetic moment is μ eff = 23.22 μB per formula unit (10.36 μB per Dy atom).

Magnetic Properties of Nd12Co6Pb Compound

Abstract The magnetic and magnetocaloric properties for the Nd 12 Co 6 Pb compound were investigated. The Curie temperature T C of the magnetic transition of Nd 12 Co 6 Pb compound is 194 K. The experimentally determined magnetic effective paramagnetic moment is μ eff = 12.36 μ B per formula unit (3.49 μ B per Nd atom). The maximum magnetic entropy change in the low magnetic field changes of 0 ∼ 2 T for the Nd 12 Co 6 Pb compound is about 215.0 J · mole −1 ·K −1 .