In-situ observation of melting and recrystallization to a high-pressure phase of MoO<sub>3</sub> induced by nanosecond laser shock-compression
POSTER
Abstract
Molybdenum(VI) oxide (MoO3) is a layered n-type wide bandgap semiconductor and has attracted attention in energy-related catalysis applications. It is important to investigate the structural response in various extreme environments. In the present study, the structural changes in MoO3 under high-pressure and high-temperature conditions induced by laser shock compression were investigated via in situ XRD using ultra-short X-ray pulses from an XFEL. When the sample was shock-compressed at pressures above 61 GPa, the Bragg peaks in the XRD profile first weakened as the shock wave propagated through the sample, and a broad halo pattern appeared in the profile indicating melting of the sample. Recrystallization of liquid MoO3 to α-MoO3 phase with MoO3-II was observed on nanosecond timescales during pressure release.
*The XFEL experiments were performed at the BL3 beamline of SACLA with the approval of the Japan Synchrotron Radiation Research Institute (Proposal No. 2023A8008, 2023A8611, 2023A8057). A part of the results were obtained using a high-power nanosecond laser deployed at SACLA by Institute of Laser Engineering of Osaka University. This work is in part supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI (Grants No. 23K04389, 20H00139, 22F22707, 16H01119, 21H01677, 17K18999, 17H04820). This work was supported by JSPS Core-to-Core Program (Grant No. JPJSCCA20230003).
Presenters
-
Hiroaki Kishimura
- National Defense Academy