Discontinuity of the phonon mode frequency temperature dependence caused by a zero-gap state in HgCdTe alloys

Józef Cebulski 1Augusto Marcelli 1,2Eugen M. Sheregii 1M Piccinini 2

1. University of Rzeszow, Institute of Physics, Rejtana 16, Rzeszów 35-310, Poland
2. °Laboratori Nazionali Frascati INFN (INFN), Via E. Fermi 40, Frascati 00044, Italy

Abstract

Quasi-binary alloy HgCdTe (MCT) form a continuous series of solid solutions of
Hg1-xCdxTe over x = 0 to 1 with zinc-blend crystalline structure1. In these alloys a band inversion and, as a result, a zero-gap state Eg ≡ G6 – G8 = 0 is realised as a composition varies from HgTe to CdTe. The zero-gap state depends on temperature too because there are several dependences Eg (x,T) for that is realised Eg = 0. These type of peculiarity can be realised by changing of Eg using press or temperature.

In this work are presented experimental results of optical reflectivity in far-infrared region (FIR) in wide interval of temperature (from 10 K to 290 K with step 10 K) for sample of Hg1-xCdxTe (x=0.115). For observation of effects described above a synchrotron radiation  FIR source has a great advantage as compared with the classical sources, intensity of which drops abruptly in this spectral region. Obtained results evidently show that frequencies of optical phonon modes have discontinuity in their temperature dependence when the zero-gap state takes place.

1.R. Dornhaus and G. Nimtz, Narrow Gap Semiconductors, Springer-Verlag, Berlin 1985,     v. 98, p. 159.

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: http://science24.com/paper/15813 must be provided.

 

Related papers
  1. Far-infrared reflectivity as a probe of point defects in Zn- and Cd-doped HgTe
  2. Magnetophonon resonance in double quantum wells
  3. Influence of hydrogen on hydrogenated cadmium telluride optical spectra
  4.  Far-infrared reflectivity as a probe of point defects in Zn- and Cd-doped HgTe
  5. SR a brilliant sources for solid-state researches in the IR and far-IR energy domain 
  6. Additional  Phonon Modes related to intrinsic defects in CdHgTe
  7. Phonon and vibrational spectra of real crystals obtained using the synchrotron radiation
  8. Influence of hydrogen on optical spectra of hydrogenated CdTe
  9. The local crystalline structure of ZnCdTe alloys obtained by Far Infrared Synchrotron Radiation measurements
  10. Defects induced by oxygen and hydrogen in CdTe crystals

Presentation: Poster at E-MRS Fall Meeting 2008, Symposium J, by Eugen M. Sheregii
See On-line Journal of E-MRS Fall Meeting 2008

Submitted: 2008-05-13 07:58
Revised:   2009-06-07 00:48
Google
 
Web science24.com
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine