The phase diagram for the YTaO₄-ZrO₂ quasi-binary has been determined up to 1600 °C. There are three distinct compositional regimes: an extensive YTaO₄ solid solution, an extensive ZrO₂ solid solution and a two-phase intermediate region. The addition of ZrO₂ to YTaO₄ decreases the M–T transition temperature almost linearly from 1426 °C to approximately 450 °C at the solubility limit (∼28 mol% ZrO₂), and then remains constant until the ZrO₂ solid solution phase boundary is reached. Within the intermediate region, there exists an extensive two-phase tetragonal (T + t) phase field above the M–T transformation temperature. The transformation exhibits no hysteresis on heating and cooling but nonetheless there is a distribution with temperature in the mass fraction of the monoclinic and tetragonal phases so no unique transformation temperature can be identified. No other high temperature phases were observed but it is suggested that a higher temperature solid solution phase is likely above 1700 °C, based on the similarity in crystallographic relationship between the two tetragonal solid solution structures.

YTaO ₄ -ZrO ₂准二元的相图已经确定到1600°C。存在三种不同的组成方案：广泛的YTaO ₄固溶体，广泛的ZrO ₂固溶体和两相中间区域。添加的ZrO ₂至YTaO ₄降低了M-Ť从1426℃的转变温度几乎线性地到约450℃，在溶解度极限（~28摩尔％的ZrO ₂），然后保持恒定，直到的ZrO ₂的固溶体相达到边界。在中间区域内，存在一个广泛的两相四边形（T  +  t）在M–T相变温度以上的相场。该转变在加热和冷却时没有滞后现象，但是在单斜相和四方相的质量分数中存在随温度的分布，因此无法确定独特的转变温度。没有观察到其他高温相，但根据两个四方固溶体结构之间晶体学关系的相似性，建议更高的固溶相可能高于1700°C。