Pressure-dependent structure of the null-scattering alloy Ti_0.676Zr_0.324

The room temperature structure of the alloy (Formula presented.) was measured by X-ray diffraction under compression at pressures up to (Formula presented.). This alloy is used as a construction material in high pressure neutron-scattering research and has a mean coherent neutron scattering length of zero, that is, it is a so-called null-scattering alloy. A broad phase transition was observed from a hexagonal close-packed α-phase to a hexagonal ω-phase, which started at a pressure of (Formula presented.) and was completed by (Formula presented.). The data for the α-phase were fitted by using a third-order Birch–Murnaghan equation of state, giving an isothermal bulk modulus (Formula presented.) and pressure derivative (Formula presented.). The results will help to ensure that accurate structural information can be gained from in situ high pressure neutron diffraction work on amorphous and liquid materials where the (Formula presented.) alloy is used as a gasket material.