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Title

Molecular dynamics investigation of vibrational properties of zeolite ZSM-5-based amorphous material A. B. Mukhopadhyay, C. Oligschleger,
M. Dolg

Physical Review B (Condensed Matter and Materials Physics -1(II))
Phys. Rev. B 68, 024205 (2003)



Email:Prof. Dr. F. M. Dolg
Mrs. A. Basu Mukhopadhyay
Prof. Dr. C. Oligschleger

 

Abstract

(Received 12 February 2003; revised 19 May 2003; published 30 July 2003)

Results of molecular dynamics simulations on vibrational properties of zeolite ZSM-5-based amorphous solids are presented. The vibrational density of states was determined for different extents of amorphization. Amorphization is found to smoothen the density of states and leads to especially large effects in the high-frequency region between 30 and 40 THz. Analysis of the contributions of atom types shows an overall dominance of oxygen, except in the frequency region between 23 and 27 THz where silicon contributes nearly equally strong. The vibrational modes are analyzed by projecting them on those of the SiO4 and Si-O-Si subunits, and individual frequency-dependent contributions of stretching, bending, and rotation are discussed.

 

Keywords

 
zeolites; amorphous state; vibrational modes; molecular dynamics method; amorphisation