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arXiv · 0910.5175

Pressure-induced phonon-freezing in the ZnBeSe alloy: a study via the percolation mesoscope

Gopal K. Pradhan·Chandrabhas Narayana·Olivier Pages·Abedalhasan Breidi·Jihane Souhabi·Andrei Viktor Postnikov·Fouad El Haj Hassan·Sudip K. Deb·Franciszek Firszt·Wojtek Paszkowicz·Abhay Shukla
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Abstract

We use the 1-bond -> 2-phonon percolation doublet of zincblende alloys as a mesoscope for an unusual insight into their phonon behavior under pressure. We focus on (Zn,Be)Se and show by Raman scattering that the original Be-Se doublet at ambient pressure, of the stretching-bending type, turns into a pure-bending singlet at the approach of the high-pressure ZnSe-like rocksalt phase, an unnatural one for the Be-Se bonds. The freezing of the Be-Se stretching mode is discussed within the scope of the percolation model (mesoscopic scale), with ab initio calculations in support (microscopic scale).

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Gopal K. Pradhan, Chandrabhas Narayana, Olivier Pages, Abedalhasan Breidi, Jihane Souhabi, Andrei Viktor Postnikov, Fouad El Haj Hassan, Sudip K. Deb, Franciszek Firszt, Wojtek Paszkowicz, Abhay Shukla. 2009-10-28. Pressure-induced phonon-freezing in the ZnBeSe alloy: a study via the percolation mesoscope. https://doi.org/10.1103/physrevb.81.115207

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