1. Ultrafast Structural Dynamics along the β-γ Phase Transition Path in MnAs.
- Author
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Vidal, Franck, Yunlin Zheng, Lounis, Lounès, Coelho, Leticia, Laulhé, Claire, Spezzani, Carlo, Ciavardini, Alessandra, Popescu, Horia, Ferrari, Eugenio, Allaria, Enrico, Jialin Ma, Hailong Wang, Jianhua Zhao, Chollet, Matthieu, Seaberg, Matthew, Alonso-Mori, Roberto, Glownia, James M., Eddrief, Mahmoud, and Sacchi, Maurizio
- Subjects
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STRUCTURAL dynamics , *PHASE transitions , *EPITAXIAL layers , *X-ray diffraction , *PHONONS , *AUDITING standards - Abstract
We investigate the orthorhombic distortion and the structural dynamics of epitaxial MnAs layers on GaAs(001) using static and time-resolved x-ray diffraction. Laser-induced intensity oscillations of Bragg reflections allow us to identify the optical phonon associated with orthorhombic distortion and to follow its softening along the path towards an undistorted phase of hexagonal symmetry. The frequency of this mode falls in the THz range, in agreement with recent calculations. Incomplete softening suggests that the β-γ transformation deviates from a purely second-order displacive transition. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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