Spontaneous ordering as an intrinsic effect at the mesoscopic scale: A vibrational insight in (Zn,Be)Se by Raman scattering and first-principles calculations
| dc.creator | Pages, O. | |
| dc.creator | Postnikov, A. V. | |
| dc.creator | Chafi, A. | |
| dc.creator | Bormann, D. | |
| dc.creator | Simon, P. | |
| dc.creator | Firszt, F. | |
| dc.creator | Paszkowicz, W. | |
| dc.creator | Tournie, E. | |
| dc.date | 2006-10-25 | |
| dc.date | 2007-09-02 | |
| dc.date.accessioned | 2026-07-07T08:26:47Z | |
| dc.date.available | 2026-07-07T08:26:47Z | |
| dc.description | The recent finding of a 1-bond->2-phonon `percolation'-type behaviour in several random zincblende alloys, supporting an unsuspected 1-bond->2-mode behaviour in the bond length distribution, renews interest for a discussion of CuPt-type spontaneous ordering (CPSO) as a purely intrinsic effect. We investigate this key issue from both experimental (Raman scattering) and theoretical (first-principles bond length and phonon calculations) sides, focusing on Zn[1-x]Be[x]Se (0<x=0.92). Its large contrast in cation-anion bond lengths should stimulate CPSO to some extent, and is at the origin of a uniquely well-resolved 1-bond->2-phonon behaviour for the Be-Se species. Based on percolation, CPSO finds a previously missing natural explanation, at the mesosocopic scale. Also, the transfer of oscillator strength from the high- to the low-frequency Be-Se mode in the Raman spectra potentially emerges as a sensitive probe of CPSO in ZnBeSe. First-principles calculations indicate that the transfer is completed for the value of the long range order parameter of eta~0.5 in ZnBeSe2 (x~0.5), corresponding to a pure 1-bond->1-mode behaviour. With further ordering the alloy is forced to re-adopt a non-rewarding 1-bond->2-mode behaviour, due to the formation of ZnSe/BeSe micro-domains in the crystal. Therefore eta~0.5 appears as an intrinsic limit to CPSO in ZnBeSe2, and possibly in stoichiometric alloys in general. | |
| dc.description | revised version on 16 pages; 7 unchanged figures | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0610682 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0610682 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/137058 | |
| dc.subject | Materials Science | |
| dc.title | Spontaneous ordering as an intrinsic effect at the mesoscopic scale: A vibrational insight in (Zn,Be)Se by Raman scattering and first-principles calculations | |
| dc.type | text |