DYNAMICAL PROPERTIES OF AN ATOMIC INTERFACE BETWEEN bcc LATTICES

A study of the phonon contribution to the interface properties between two bcc dissimilar solids is presented. The model system is obtained by the juxtaposition of two semi-infinite harmonic bcc lattices. The interface observables are numerically calculated for different cases of masses and elastic softening to hardening, to investigate how the local dynamics can respond to many environmental microscopic changes in the field interfacial domain. The theoretical formalism using simultaneously the Green's functions and the matching method is employed to describe the dynamics of the bcc system, the complete evanescent and the propagating fields. A calculation is presented for the vibration localized states, the coherent phonon transmission and the density of states (DOS), as element of a Landauer–Buttiker type scattering matrix. The system dynamics, the phonon scattering and the transmission spectra via the interface domain between bcc lattices and the DOS are analyzed as function of the atomic masses and the elastic force constants occurring in the nanojunction zone of the model system. Our results show that the interface zone is an effective phonon splitter and suggest that its characteristics may be controlled by varying its nanometric parameters. The observed fluctuations are due to the coherent coupling between continuum and discrete states induced by the interface domain.

[1]  B. Bourahla,et al.  Dynamic properties of integrated nanostructure on metallic surface , 2012 .

[2]  M. Belhadi,et al.  Phonons heat transport at an atomic well boundary in ultrathin solid films , 2011 .

[3]  B. Bourahla,et al.  Phonon scattering in quasi-one-dimensional structure , 2011 .

[4]  B. Bourahla,et al.  Vibration dynamics of single atomic nanocontacts , 2007 .

[5]  L. Zhigilei,et al.  Effects of temperature and disorder on thermal boundary conductance at solid-solid interfaces: Nonequilibrium molecular dynamics simulations , 2007 .

[6]  Wei Cheng,et al.  Lattice dynamics investigations of phonon thermal conductivity of Si∕Ge superlattices with rough interfaces , 2006 .

[7]  A. Khater,et al.  Vibration spectra of soliton boundaries separating nanostructured 2D hexagonal lattice domains , 2005 .

[8]  R. Tigrine,et al.  Dynamical Properties of the Interface Between Two Thin Films , 2005 .

[9]  M. Belhadi,et al.  TRANSMISSION OF PHONON MODES IN QUASI-ONE-DIMENSIONAL WAVEGUIDES VIA DOUBLE L-SHAPED JOINT NANOSTRUCTURES , 2004 .

[10]  A. Rappe,et al.  Structure and vibrations of the vicinal copper (211) surface , 1997, cond-mat/9712071.

[11]  A. Khater,et al.  Calculation of surface phonons and resonances: the matching procedure revisited: I , 1987 .

[12]  L. Dobrzynski,et al.  Simple calculation of the mean square displacements of volume and surface atoms of face-centered cubic crystals , 1972 .

[13]  P. Dean.  The Vibrational Properties of Disordered Systems: Numerical Studies , 1972 .

[14]  J. Behari,et al.  Modified Angular Force Model in the Studies of Lattice Dynamics of B C C Metals: an Application to Sodium , 1970 .

[15]  S. K. Joshi,et al.  Model for the Lattice Dynamics of Metals and Its Application to Sodium , 1963 .

[16]  R. F. Wallis,et al.  Surface effects on lattice vibrations , 1963 .

[17]  Antony Virlouvet.  Dynamique vibrationnelle d'une marche isolee en surface , 1997 .

[18]  J. Behari,et al.  LATTICE DYNAMICS OF SOME BCC TRANSITION METALS. , 1972 .

[19]  V. Heine,et al.  Pseudopotential Theory of Cohesion and Structure , 1970 .

[20]  A. Maradudin.  Theoretical and Experimental Aspects of the Effects of Point Defects and Disorder on the Vibrations of Crystals—1 , 1966 .

[21]  E. Montroll,et al.  The vibration spectra of disordered lattices , 1959 .