Abstract The solid state phase diagram for the equilibria of the ternary Ta-Ti-P system was established by X-ray powder diffraction at T = 1070 K in the region up to 67 at.% P. Isostructural compounds Ta3P and Ti3P (both Ti3P-type) form a continuous series of substitution-type solid solutions. The majority of binary compounds form substitution-type solid solutions, in which the substitution of Ti for Ta, or Ta for Ti, takes place. The crystal structure investigation of the new ternary phosphide demonstrates that this phase is isotypical to the OsGe2 structure type and has a small homogeneity range, which can be described by the formula Та1-xТіxР2 (x = 0.07(3)−0.145(7), space group C2/m, a = 8.8556(9)−8.8446(2), b = 3.2654(4)−3.2605(1), c = 7.4846(8)−7.4741(1) A, β = 119.307(2)−119.308(1)°). Our density functional theory (DFT) electronic structure calculations show that the stoichiometric composition TaP2 has no electronic instability, although it does not exist under the thermal conditions used in present study. The addition of a small amount of Ti leads to a ternary phase Та1-xТіxР2 (x = 0.07(3)−0.145(7)) with a higher thermal stability compared to TaP2.

中文翻译：

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钽、钛和磷在 1070 K 下的相互作用：相图和结构化学

摘要 通过 X 射线粉末衍射在 T = 1070 K 在高达 67 at.% P 的区域建立了三元 Ta-Ti-P 系统平衡的固态相图。同构化合物 Ta3P 和 Ti3P（均为 Ti3P -type) 形成一系列连续的置换型固溶体。大多数二元化合物形成取代型固溶体，其中发生 Ti 取代 Ta 或 Ta 取代 Ti。新型三元磷化物的晶体结构研究表明，该相与 OsGe2 结构类型同型，且具有较小的同质性范围，可用公式 Та1-xТіxР2 (x = 0.07(3)−0.145(7),空间群 C2/m, a = 8.8556(9)−8.8446(2), b = 3.2654(4)−3.2605(1), c = 7.4846(8)−7.4741(1) A, β = 119.307(2)− 119.308(1)°)。我们的密度泛函理论 (DFT) 电子结构计算表明，化学计量成分 TaP2 没有电子不稳定性，尽管它在本研究中使用的热条件下不存在。添加少量 Ti 导致三元相 Та1-xТіxР2 (x = 0.07(3)−0.145(7)) 与 TaP2 相比具有更高的热稳定性。