“…The specific method is to evaluate the free energy of different volumes at a certain temperature, calculated by 11 groups of phonons (
= 5% and 1% change in the range) in different volumes and then fitted to third‐order Birch–Murnaghan equation of states equation,
65 as shown in Figures S2–S4. The CTEs of the Nb 2 AN (A = Si, Ge, Sn) phases are calculated as shown in Figure 4A and compared with YSZ,
66 protective layer material Al 2 O 3 ,
66 bonding layer NiCoCrAlY,
66 and Ni‐based superalloy materials
67 . It can be found that the CTEs of Nb 2 AN (A = Si, Ge, Sn) phase increase with the rise of temperature.…”