High pressure and high temperature in situ X-ray diffraction study on the structural stability of tantalum disilicide

The structural stability in TaSi2 was investigated by in situ angle dispersive X-ray diffraction (AD-XRD), which shows that the structure is stable even up to about 50.0 GPa at room temperature. However, under high pressure and high temperature (HPHT) conditions it was revealed that TaSi2 could undergo a structural phase transition from a C40-type hexagonal phase to a metastable phase after a temperature quench from 573 K at 10.6 GPa.

► The crystal structure is stable for C40-type TaSi2 up to 50.0 GPa at room temperature.
► C40-type TaSi2 presents anisotropic compressibility behavior under high pressure.
► C40-type TaSi2 undergo a structural phase transition after a temperature quench.