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Model of Lattice Dynamics of Cd 3 As 2 Single Crystals
Author(s) -
Weszka J.
Publication year - 1999
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/(sici)1521-3951(199902)211:2<605::aid-pssb605>3.0.co;2-y
Subject(s) - brillouin zone , tetragonal crystal system , raman spectroscopy , condensed matter physics , lattice (music) , physics , raman scattering , crystal (programming language) , crystal structure , crystallography , optics , chemistry , acoustics , programming language , computer science
Raman scattering (RS) in α‐Cd 3 As 2 single crystals has been studied. Its complex structure with the body centered tetragonal (b.c.t.) unit cell comprising as many as 160 atoms of the constituents is treated in terms of a manifold of 16 imperfect zincblende‐like units. the choice of InAs crystal as the zincblende counterpart of the α‐Cd 3 As 2 crystal is discussed. A model of its lattice dynamics based on folding back dispersion branches of InAs crystal into the b.c.t. Brillouin zone of α‐Cd 3 As 2 crystal is proposed. The low frequency features observed in the RS spectra have been derived by folding TA branches of InAs along with Δ, Λ and Σ directions and mapping of TA(X) and TA(L) zincblende states onto the Γ point of the b.c.t. Brillouin zone (BZ). Higher intensities of these modes correspond rather well with flatness of TA branches. The modes with frequencies higher than 80 cm —1 are derived from the folded, LA, TO and LO branches along Δ, Λ and Σ directions. Their lower intensities are attributed to higher dispersion of LA, TO and LO branches.