Determination of the phase boundary of the omega to beta transition in Zr using in situ high-pressure and high-temperature X-ray diffraction

•X-ray diffraction patterns of zirconium were measured by the synchrotron experiments.•High-pressure experiments were performed by an external-heated diamond anvil cell.•Phase diagram of zirconium was determined at high pressures and high temperatures.•Phase boundary between omega and beta transition has a negative dP/dT slope.

The high-pressure behavior of zirconium has been examined using the synchrotron X-ray diffraction technique to a pressure of 38 GPa and a temperature of 800 K employing a hydrothermal diamond anvil cell technique. The structural transition from the ω to the β phase was observed. This transition has a negative dP/dT gradient, which is in general agreement with those reported in previous studies. The transition boundary was determined to be, P (GPa)=41.2–0.025×T (K). The negative slope of the transition, dP/dT, determined in our study using the diamond anvil cell technique was less than half that estimated by the previous study using a large press apparatus.

Graphical abstractExperimental results and phase boundary of the ω–β transition in Zr.Figure optionsDownload full-size imageDownload as PowerPoint slide