Phase transitions in the group-IV transition-metal zirconium were studied by the energy-dispersive x-ray-diffraction technique with a synchrotron source to a pressure of 32 GPa. A first-order phase transition between an ω phase and a bcc phase (isostructural with group-V transition elements) was observed during compression and decompression in a pressure range of 30±2 GPa, which is in qualitative agreement with the recent first principles theoretical predictions. The observation of the bcc phase in Zr (a group-IV element) under pressure at room temperature signifies a pressure-induced electronic configuration similar to that of a group-V element.

• Received 22 November 1989

DOI:https://doi.org/10.1103/PhysRevLett.64.204