Study On The Isothermal Section Of The Gd-Co-Sn Ternary System And On The Vertical Section Of Cosn-Gdcosn In The System

Phase relations in the Gd-Co-Sn ternary system at 773K and the verticalsection of CoSn-GdCoSn in the system have been investigated in this work. Themain contents of them were related as followed:1. The isothermal section of Gd-Co-Sn ternary system at 773KThe phase relationships in the Gd-Co-Sn ternary system at 773K havebeen investigated by means of X-ray powder diffraction. The existence of 13binary compounds Gd₅Sn₃, Gd₅Sn₄, Gd₁₁Sn₁₀, GdSn₂, Co₃Sn₂, CoSn, Gd₂Co₁₇,Gd₂Co₇, GdCo₃, GdCo₂, Gd₄Co₃, Gd₁₂Co₇, Gd₃Co and six ternary compoundsGd₆Co₂Sn, GdCo₃Sn, GdCoSn, GdCo₂Sn₂, GdCo₆Sn₆ and Gd₃Co₄Sn₁₃ wereconfirmed. There are 13 single-phase regions, 16 two-phase regions and 24three-phase regions in this 773K isothermal section. A solid solution ofGdCo₃Sn was found. The solid solubility range of Sn in GdCo₃Sn is 20-27 at.%.2. Vertical section of CoSn-GdCoSn in the Gd-Co-Sn systemThe vertical section of CoSn-GdCoSn (≤33.3at.%Gd) in the Gd-Co-Snternary system was investigated by X-ray diffraction and differential thermalanalysis. The existence of four compounds CoSn, GdCo₆Sn₆, GdCo₂Sn₂ and GdCoSn were confirmed. Two allotropic transformations in compoundsGdCo₆Sn₆ and GdCoSn were found. The allotropic transformation of GdCo₆Sn₆from high temperature hexagonal structure to low temperature monoclinicstructure occurs at 552℃, while the allotropic transformation of GdCoSn fromhigh temperature tetragonal structure to low temperature orthorhombic structureoccurs at 966℃. The compound GdCo₆Sn₆ melts congruently at 1082℃. Twoeutectic reactions and one peritectic reaction have been observed in this system.