Isothermal Section Of The GD-MN-SI Ternary System At500℃

The isothermal section of the Gd-Mn-Si ternary system was investigated by X-ray diffraction and scanning electric microscope. The phase diagram of the Gd-Mn-Si ternary system at500℃was established. All15binary compounds in this system were showed as:α-GdSi2, GdSi1.67, GdSi, Gd5Si4, Gd5Si3, MnSi, Mn27Si47, MnSi, Mn5Si3, Mn5Si2, Mn3Si, Mn9Si2, Mn6Si. Binary compounds Gd3Si4and Gd2Si3were not found in this system at500℃. Gd3Si4would be found after a special thermal processing, and Gd2Si3now are presented as a-GdSi2. All these binary compounds were certified directly by XRD data of samples located in the binary system or indirectly by XRD data from nearby three-phase regions. Ternary compounds GdMnSi with a CeFeSi structure type and GdMn2Si2with a ThCr2Si2structure type were reconfirmed. No evidence showed that ternary compound GdMnSi2existed in this system at500℃. No new compounds were found. This ternary system consists of20three-phase regions. GdSi2is at its low-temperature state at500℃and it remains this state while temperature is up to800℃. Gd2Mn3Si5exists at a temperature higher than700℃...