%0 Journal Article
	%A Alpana Tiwari and  N. K. Gaur
	%D 2014
	%J International Journal of Materials and Metallurgical Engineering
	%B World Academy of Science, Engineering and Technology
	%I Open Science Index 92, 2014
	%T Lattice Dynamics of (ND4Br)x(KBr)1-x Mixed Crystals
	%U https://publications.waset.org/pdf/10003786
	%V 92
	%X We have incorporated the translational rotational (TR)
coupling effects in the framework of three body force shell model
(TSM) to develop an extended TSM (ETSM). The dynamical matrix
of ETSM has been applied to compute the phonon frequencies of
orientationally disordered mixed crystal (ND4Br)x(KBr)1-x in (q00),
(qq0) and (qqq) symmetry directions for compositions 0.10≤x≤0.50
at T=300K.These frequencies are plotted as a function of wave vector
k. An unusual acoustic mode softening is found along symmetry
directions (q00) and (qq0) as a result of translation-rotation coupling.
	%P 886 - 889