The MnS–Tb₂S₃ phase diagram has been plotted by using physico-chemical methods of analysis. This diagram refers to the transition type from the eutectic system MnS–Gd₂S₃ to the systems with the formation of intermediate compounds. Two MnTb₄S₇ and MnTb₂S₄ complex sulfides are formed in the MnS–Tb₂S₃ system. The thermal effects of solid-phase decomposition of complex sulfides are as follows: ΔH = 27.4 kJ/mol at 1643 K for MnTb₄S₇ and ΔH = 16 kJ/mol at 1574 K for MnTb₂S₄. The solubility of MnS in γ-Tb₂S₃ at 1650 K is 16 mol.%, and 5 mol.% of MnS is dissolved in α-Tb₂S₃ at 1170 K. The solubility of Tb₂S₃ in α-MnS-based solid solution (SS) is 6 mol.% at 1650 K and 3 mol.% of Tb₂S₃ at 1170 K. The temperature of the γ-Tb₂S₃ solid solution eutectoid decomposition is equal to 1350 K, and the composition of the eutectoid is 87 mol.% of Tb₂S₃. The coordinates of the eutectic between MnS-based solid solution and γ-Tb₂S₃-based solid solution is assumed to be equal to 27 mol.% of Tb₂S₃ and 1666 K. Calculations of the liquidus line, carried out using the Van Laar's equation, are in agreement with the experimental data. The Gibbs excess partial energies are calculated for the MnS–Tb₂S₃ system, and their negative values are correlated with the formation of two complex sulfides MnTb₂S₄ and MnTb₄S₇ in the system.

MnS–Tb ₂ S ₃相图已使用理化分析方法绘制。该图是指从共晶体系MnS–Gd ₂ S ₃到形成中间化合物的体系的过渡类型。在MnS–Tb ₂ S ₃系统中形成了两个MnTb ₄ S ₇和MnTb ₂ S ₄复合硫化物。复杂硫化物的固相分解的热效应如下：MnTb ₄ S ₇在1643 K时ΔH= 27.4 kJ / mol，在MnTb ₂ S ₄在1574 K时ΔH= 16 kJ / mol。MnS的在γ-Tb的溶解度₂小号₃在1650 K为16摩尔％，和MnS的5摩尔％溶解在α-Tb的₂小号₃在1170 K. Tb中的溶解度₂小号₃在α- MnS系固溶体（SS）为6摩尔％在1650 K和Tb中的3摩尔％₂小号₃在1170 K.的γ-Tb的温度₂小号₃固溶体共析分解等于1350 K，所述共析物的组成为Tb ₂ S _3的87摩尔％。之间的共晶的坐标MnS系固溶体和γ-Tb的₂小号₃基固溶体假定等于Tb ₂ S ₃和1666 K的27摩尔％。使用Van Laar方程进行的液相线的计算与实验数据一致。计算了MnS–Tb ₂ S ₃系统的吉布斯过量部分能量，其负值与系统中两种复合硫化物MnTb ₂ S ₄和MnTb ₄ S ₇的形成相关。