The doping with Cu in the Sb-Se material system can effectively reduce power consumption and improve data retention ability of the PCRAM (Phase-Change Random-Access Memory) material. However, no thermodynamic study of the Cu-Sb-Se system has been reported. Therefore, in this work the Cu-Sb-Se system was modeled using the CALPHAD (CALculation of PHAse Diagrams) method. The excess Gibbs energies of solution phases, including liquid and FCC were expressed by the Redlich-Kister polynomial. Two-sublattice model (Cu,Se)₂Se was used to describe the solid solution of binary intermetallic compounds, i.e. α-Cu₂Se and β-Cu₂Se in Cu-Sb-Se ternary system. The compounds, e.g. η(Cu₂Sb), β(Cu₃Sb), Sb₂Se₃, α-CuSe, β-CuSe, Pe(Cu₃SbSe₄) and C(CuSb₃Se₅) were described as stoichiometric compounds. The temperature of the eutectic reaction γ(Cu₁₇Sb₃) = (Cu) + δ(Cu₄Sb) in the Cu-Sb system and the temperature of the invariant reaction L1 = L2 + (Sb) in the Sb-Se system were adjusted. A set of self-consistent thermodynamic parameters for the Cu-Sb-Se system was obtained, and the 623, 673, 723, 773, 873 and 973 K isothermal sections, and the liquidus projection and invariant reactions for this ternary system have been calculated.

Sb-Se材料体系中Cu的掺杂可以有效降低PCRAM（相变随机存取存储器）材料的功耗并提高数据保存能力。然而，尚未报道Cu-Sb-Se体系的热力学研究。因此，在这项工作中，使用 CALPHAD（PHAse 图计算）方法对 Cu-Sb-Se 系统进行建模。溶液相（包括液体和 FCC）的过量吉布斯能量由 Redlich-Kister 多项式表示。双亚晶格模型(Cu,Se) ₂ Se用于描述二元金属间化合物α -Cu ₂ Se和β -Cu ₂ Se在Cu-Sb-Se三元体系中的固溶体。化合物，例如 η(Cu ₂ Sb)、β (Cu ₃ Sb)、Sb ₂ Se ₃、α -CuSe、β -CuSe、Pe(Cu ₃ SbSe ₄ ) 和 C(CuSb ₃ Se ₅ ) 被描述为化学计量化合物。Cu-Sb系中的共晶反应温度γ (Cu ₁₇ Sb ₃ )=(Cu)+  δ (Cu ₄ Sb)和Sb-Se系中的不变反应温度L1=L2+(Sb)进行了调整。获得了Cu-Sb-Se体系的一组自洽热力学参数，并计算了该三元体系的623、673、723、773、873和973 K等温段，以及液相线投影和不变反应。