The Isothermal Section Of The Gd-Ge-Sb Ternary System At 773K And The Crystal Structure And Thermal Expansion Behavior Of CuSb₂Ti₅

Phase relations in the Gd-Ge-Sb ternary system at 773K have beeninvestigated in this work. The crystal structure and thermal expansion behaviorof a compound CuSb₂Ti₅ have also been studied. The main contents were asfollows:1 The isothermal section of Gd-Ge-Sb ternary system at 773KThe isothermal section of the phase diagram of the Gd-Ge-Sb ternarysystem at 773K has been investigated mainly by X-ray powder diffraction withthe aid of diffirrential thermal analysis in this work. This isothermal sectionconsists of thirteen single-phase regions, twenty five two-phase regions andthirteen three-phase regions.The thirteen single-phase regions are:α(Gd),β(Gd₅Sb₃),γ(Gd₄Sb₃),δ(GdSb),ε(Sb),ζ(Ge),η(Gd₃Ge₅),θ(Gd₂Ge₃),ι(GdGe),κ(Gd₅Ge₄),λ(Gd₅Ge₃),μ(Gd₆Ge_4.33Sb_11.7),ν(～Gd₃₅Ge₅₈Sb₇).The twenty five two-phase regions are:α+β,β+γ,γ+δ,δ+ε,ε+ζ,ζ+η,η+θ,θ+ι,ι+κ,κ+λ,λ+α,λ+β,λ+γ,κ+δ,ι+δ,θ+δ,θ+δ,η+δ,ζ+δ,η+δ,η+ν,ζ+ν,μ+δ,ζ+μ,μ+ε.The thirteen three-phase regions are:α+β+λ,β+γ+λ,λ+κ+γ,γ+δ+κ,κ+ι+δ, ι+θ+δ,θ+η+δ,η+ν+δ,η+ζ+ν,ν+ζ+δ,ζ+μ+δ,δ+μ+ε,μ+ε+ζ.According to the results of experiment, this isothermal section consists oftwo ternary compound. One of them is Gd₆Ge_4.33Sb_11.7, and the other one is anew ternary compound, which is maybe～Gd₃₅Ge₅₈Sb₇.2 Crystal structure and thermal expansion behavior of CuSb₂Ti₅The crystal structure and thermal expansion behavior of a compoundCuSb₂Ti₅ have been investigated by X-ray powder diffraction and refined byRietveld profile fitting method. The compound crystallizes in the tetragonal,space group I4/mcm (No. 140) with the Si₃W₅ structure type and latticeparameters a=1.04804(2)nm, c=0.52424(2)nm, z=4 and D_calc=6.301 g/cm³.Rietveld refinement result was R_p=8.96%, R_wp=12.05% and S=1.97. Thelattice thermal expansion characteristics of CuSb₂Ti₅ have been studied in thetemperature range of 298-773K by the high temperature X-raydiffraction(HTXRD). The thermal expansions coefficientsα_a,α_c andα_v are: 9.6×10^-6, 1.8×10^-5 and 3.8×10^-5K^-1, respectively.