Experimental determination of the phase relations in the Mn–As–Pr ternary system at 700 °C

• Published in: Journal of alloys and compounds 2018-04, Vol.741, p.975-980
• Main Authors: Gu, Z.F., Xu, CH.F., Hong, L.J., Ma, D.D., Cheng, G., Yao, Q.R., Hu, K., Lin, R.S., Zhang, W.F.
• Format: Article
• Language: English
• Subjects: Chemical composition; Diffraction; Mn–As–Pr system; Phase diagram; Phase transitions; Scanning electron microscopy; SEM; Ternary systems; X-ray diffraction; X-rays
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2018.01.171

Isothermal section at 700 °C of the ternary Mn–As–Pr system was established by means of X-ray diffraction, scanning electron microscopy and energy dispersion spectroscopy techniques. This isothermal section consists of 11 single-phase, 20 two-phase regions, and 10 three-phase regions. The maximum solubility of Pr in MnAs is less than 1.25 at.%Pr and that of Mn in AsPr is less than 3 at.%Mn. The phase Mn4As3 does not exist under the applied experimental conditions. An existence of a new ternary phase Ω is observed in the Mn–As–Pr system at 700 °C. Since all the attempts to prepare a single ternary phase (Ω) sample were unsuccessful, the structure of phase Ω has not been solved and its chemical composition is approximately defined as Mn16As25Pr9 from the SEM-EDS analyses. •The isothermal section of the Mn–As–Pr system at 700 °C is established.•The formation of new ternary phase Ω with a composition Mn16As25Pr9 is determined.•The maximum solubilities of Pr in MnAs and Mn in AsPr are determined.