Spontaneous ordering as an intrinsic effect at the mesoscopic scale: A vibrational insight in (Zn,Be)Se by Raman scattering and first-principles calculations

Details Spontaneous ordering as an intrinsic effect at the mesoscopic scale: A vibrational insight in (Zn,Be)Se by Raman scattering and first-principles calculations Spontaneous ordering as an intrinsic effect at the mesoscopic scale: A vibrational insight in (Zn,Be)Se by Raman scattering and first-principles calculations

2006-10-25

arxiv.org/abs/cond-mat/0610682v3

Physics

Condensed Matter

Materials Science

revised version on 16 pages; 7 unchanged figures

Scientific paper

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 (02-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.

Affiliated with

Also associated with

No associations

Rating

Spontaneous ordering as an intrinsic effect at the mesoscopic scale: A vibrational insight in (Zn,Be)Se by Raman scattering and first-principles calculations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Spontaneous ordering as an intrinsic effect at the mesoscopic scale: A vibrational insight in (Zn,Be)Se by Raman scattering and first-principles calculations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spontaneous ordering as an intrinsic effect at the mesoscopic scale: A vibrational insight in (Zn,Be)Se by Raman scattering and first-principles calculations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-378138