Investigation On The Phase Equilibria Of Ternary Systems In The Mn-Si-(Ge,Sn) System

The isothermal sections of the Ge-Mn-Si ternary system at500℃and Mn-Si-Sn ternary system at400℃and750℃were constructed using X-ray powder diffraction (XRD), scanning electron microcopy(SEM) and energy dispersive X-ray analysis (EDS). The maximum solid solubilities of related compounds were determined.No ternary compound was observed in Ge-Mn-Si ternary system at500℃, ternary solid solution, Mn5(Ge, Si)3, formed between Mn5Ge3and Mn5Si3(Mn5Si3-type structure). The existences of seven binary compounds in the Mn-Si binary system:Mn6Si、Mn9Si2, Mn3Si, Mn5Si2, Mn5Si3, MnSi, Mn27Si47were confirmed at500℃and four binary Mn-Ge compounds:Mn3.4Ge, Mn5Ge2, Mn5Ge3, Mn11Geg were observed at this temperature. This isothermal section consists of14single-phase regions,26two-phase regions and11three-phase regions. The solubilities of Ge in Mn6Si, Mn9Si2, Mn3Si, Mn5Si2, MnSi, Mn27Si47and Si were measured to be about7.7,4.8,8.1,13.5,10.8,0.89and12.98at.%Ge, respectively. The solubilities of Si in Mn34Ge, Mn5Ge2, Mn11Ge8and Ge were determined to be8.1,13.5,5.2and17.1at.%Si, respectively.There isn’t ternary compound in Mn-Si-Sn system too. The low-temperature binary compound Mn3Sn2was observed at400℃. The isothermal section (Mn-Si-Sn (400℃)) consists of14single-phase regions,24two-phase regions and12three-phase regions. The solubilities of Si in Mn3Sn, Mn3Sn2, MnSn2were determined to be2.3,5,2.5at.%Sn at400℃. The high-temperature binary compound Mn2Sn was observed at750℃.There are12single-phase regions,22two-phase regions and10three-phase regions in the isothermal section of Mn-Si-Sn (750℃) ternary system. The solubilities of Si in Mn3Sn, Mn2Sn was determined to be2.4,1.9at.%Sn at750℃.