The effects of short-range order and natural microinhomogeneities on the FIR optical properties of CdxHg1-xTe

• Type: Article in International Scientific Journal
• Date: 1999

Authors

Vasilevskiy, MI (Author) Other; Belogorokhov, AI (Author) Other; Gomes, MJM (Author) Other

Journal

The Journal is awaiting validation by the Administrative Services.

Title: JOURNAL OF ELECTRONIC MATERIALS

Vol. 28

Pages: 654-661

ISSN: 0361-5235

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 3 Citations

Other information

Authenticus ID: P-001-47A

DOI: 10.1007/s11664-999-0049-3

Abstract (EN): Possible types and formation mechanisms for the correlated cation distributions in CdxHg1-xTe alloys, including short-range order (SRO) in the mixed sublattice and composition microinhomogeneities (MI), are discussed. The impact of SRO (ordering or clustering) on phonons is studied in the framework of the coherent potential approximation. It is shown that two peaks of the spectral density of phonon states with (q) over bar = 0 (HgTe-like and CdTe-like modes) move toward and away from their positions in end member crystals due to clustering and ordering, respectively. Short-range ordering also activates (HgTe-like and CdTe-like states of the Brillouin zone edge, but this effect is small. The effects of composition MI on the dielectric response due to phonons are considered and an effective dielectric function is calculated using the modified Maxwell-Garnett approach. It is shown that separate inclusions of different composition produce extra modes of the Frohlich type in FIR spectra of CdxHg1-xTe. It is argued that this is a more plausible explanation of the experimenatally observed 'cluster' mode (133 cm(-1) in Raman and 135 cm(-1) in FIR spectral than one which previously appeared in the literature and involves atomic ordering in the mixed sublattice.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8