Pseudo Binary Phase Diagram of Oxides

The equilibria of the HfO2-Ta2O5 system is of interest for applications in high temperature material systems. Compositions within this system are currently used as thermal barrier coatings, and high temperature dielectrics. Understanding of the HfO2-Ta2O5 system is also of interest for the oxidation of other ultra-high temperature materials such as HfC-TaC and HfN-TaN, etc, and where you can use the TCS Ultra-high Temperature Materials Database (TCUHTM) for analysis.

Ta2O5-HfO2

Calculated phase diagram for Ta2O5-HfO2 with experimental data

Figure 1: Calculated phase diagram for Ta2O5-HfO2 with experimental data from [2019McC].

Reference

[2019McC] S. J. McCormack, K. Tseng, R. J. K. Weber, D. Kapush, S. V. Ushakov, A. Navrotsky, W. M. Kriven, In‐situ determination of the HfO 2 –Ta 2 O 5 ‐temperature phase diagram up to 3000°C. J. Am. Ceram. Soc. 102, 4848–4861 (2019).