Lattice-dynamics and network-dynamics studies of vibrational modes in lithium-doped borate glasses

1990 ◽  
Vol 41 (11) ◽  
pp. 7767-7773 ◽  
Author(s):  
J. Deppe ◽  
M. Balkanski ◽  
R. F. Wallis
Keyword(s):  
Lattice Dynamics ◽  
Network Dynamics ◽  
Borate Glasses ◽  
Vibrational Modes

Lattice Dynamics and Network Dynamics Calculations on Vibrational Modes of Lithium Borate Glasses

1990 ◽  
Vol 210 ◽  
Author(s):  
J. Deppe ◽  
M. Balkanski ◽  
R. F. Wallis ◽  
M. Massot
Keyword(s):  
Lattice Dynamics ◽  
Structural Changes ◽  
Structural Model ◽  
Nearest Neighbor ◽  
Network Dynamics ◽  
Borate Glasses ◽  
Vibrational Modes ◽  
Good Qualitative Agreement ◽  
Covalently Bonded ◽  
The Family

AbstractThe central force nearest neighbor model for glasses is used to discuss the Raman and infrared vibrational data for the family of lithium doped borate glasses B2O3 - xLi2O. The addition of the dopant is shown to cause local structural changes, including the transformation of three-coordinated borons to four-coordinated ones. An extremely simple structural model for the glass gives good qualitative agreement with experiment. The results of lattice dynamics calculations fall within the allowed frequency band limits predicted by network dynamics. The success of this model illustrates the importance of short range order on the vibrational spectra of covalently bonded solids.

scholarly journals Influence of Doping on the Lattice Dynamics of Gallium Nitride

1999 ◽  
Vol 4 (S1) ◽  
pp. 327-332 ◽  
Author(s):  
A. Kaschner ◽  
H. Siegle ◽  
A. Hoffmann ◽  
C. Thomsen ◽  
U. Birkle ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Lattice Dynamics ◽  
Molecular Beam ◽  
High Energy ◽  
Host Lattice ◽  
Free Carrier ◽  
Vibrational Modes ◽  
Local Vibrational Modes ◽  
Secondary Ion ◽  
Mg Doped

We present results of Raman-scattering experiments on GaN doped with Si, C, and Mg, respectively, grown by molecular beam epitaxy (MBE). The influence of the different dopants on strain and free-carrier concentration was investigated. Furthermore, we report on several local vibrational modes (LVM) around 2200 cm−1 in Raman spectra of highly Mg-doped GaN. A possible explanation of these high-energy modes in terms of hydrogen-related vibrations is given. We also found a variety of new structures in the range of the GaN host lattice phonons. Secondary ion mass spectroscopy (SIMS) was applied to determine the concentration of magnesium and unintentionally incorporated hydrogen.

Structure-Sensitive Vibrations in Zeolites as Studied by Raman Scattering

1987 ◽  
Vol 111 ◽  
Author(s):  
R. G. Buckley ◽  
H. W. Deckman ◽  
J. M. Newsam ◽  
J. A. McHenry ◽  
P. D. Persans ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Lattice Dynamics ◽  
Nearest Neighbor ◽  
Low Frequency ◽  
Force Model ◽  
Vibrational Modes ◽  
Vibrational Assignments ◽  
Structure Sensitive ◽  
Bending Mode ◽  
Bond Bending

AbstractIn this paper we demonstrate the usefulness of a nearest neighbor force model for studying the structural dependence of the lattice dynamics of zeolites. Interpreting Raman scattering in the context of this model confirms earlier empirical vibrational assignments in zeolites and underlines the importance of short range forces in determining the frequencies of certain zeolite vibrational modes. The model describes fully the low frequency bond bending mode of A1 symmetry, although long range forces are shown to be required to model complete zeolite vibrational spectra.

Lattice dynamics calculations and temperature dependence of vibrational modes of ferroelastic Li2TiGeO5

2006 ◽  
Vol 18 (7) ◽  
pp. 2137-2147 ◽  
Author(s):  
M Maczka ◽  
A Sieradzki ◽  
R Poprawski ◽  
K Hermanowicz ◽  
J Hanuza
Keyword(s):  
Temperature Dependence ◽  
Lattice Dynamics ◽  
Vibrational Modes

scholarly journals LIGHT SCATTERING FROM ACOUSTIC AND LOW-FREQUENCY VIBRATIONAL MODES IN BORATE GLASSES

1982 ◽  
Vol 43 (C9) ◽  
pp. C9-541-C9-543 ◽  
Author(s):  
J. Lorösch ◽  
M. Couzi ◽  
J. Pelous ◽  
R. Vacher ◽  
A. Levasseur
Keyword(s):  
Light Scattering ◽  
Low Frequency ◽  
Borate Glasses ◽  
Vibrational Modes

THE STRUCTURE AND LATTICE DYNAMICS OF UNRECONSTRUCTED FCC (001) AND (111) METAL SURFACES

1994 ◽  
Vol 01 (01) ◽  
pp. 97-107 ◽  
Author(s):  
S.Y. TONG ◽  
Y. CHEN ◽  
K.P. BOHNEN ◽  
T. RODACH ◽  
K.M. HO
Keyword(s):  
Lattice Dynamics ◽  
Metal Surfaces ◽  
Vibrational Modes ◽  
Complete Understanding ◽  
Atom Scattering ◽  
New Information ◽  
Resolution Electron ◽  
Electron Energy Loss ◽  
Localized Vibrational Modes ◽  
Phonon Calculation

Progress in first-principles surface phonon calculation and multiple scattering phonon cross-section calculation has provided a more complete understanding of the localized vibrational modes on unreconstructed metal surfaces. A discussion of some of the new results is given focusing on how the new information resolves earlier difficulties in the interpretation of inelastic He-atom scattering (HAS) and high-resolution electron energy loss spectroscopy (EELS) data on these metal surfaces.

scholarly journals Influence of Doping on the Lattice Dynamics of Gallium Nitride

1998 ◽  
Vol 537 ◽  
Author(s):  
A. Kaschner ◽  
H. Siegle ◽  
A. Hoffmann ◽  
C. Thomsen ◽  
U. Birkle ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Lattice Dynamics ◽  
Molecular Beam ◽  
High Energy ◽  
Host Lattice ◽  
Free Carrier ◽  
Vibrational Modes ◽  
Local Vibrational Modes ◽  
Secondary Ion ◽  
Mg Doped

AbstractWe present results of Raman-scattering experiments on GaN doped with Si, C, and Mg, respectively, grown by molecular beam epitaxy (MBE). The influence of the different dopants on strain and free-carrier concentration was investigated. Furthermore, we report on several local vibrational modes (LVM) around 2200 cm-1 in Raman spectra of highly Mg-doped GaN. A possible explanation of these high-energy modes in terms of hydrogen-related vibrations is given. We also found a variety of new structures in the range of the GaN host lattice phonons. Secondary ion mass spectroscopy (SIMS) was applied to determine the concentration of magnesium and unintentionally incorporated hydrogen.

Structural Characterization Of Zeolites Using Raman Scattering

1991 ◽  
Vol 233 ◽  
Author(s):  
H. W. Deckman ◽  
J. A. Creighton ◽  
R. G. Buckley ◽  
J. M. Newsam
Keyword(s):  
Complete Lattice ◽  
Lattice Dynamics ◽  
Optically Active ◽  
Mode Frequency ◽  
Vibrational Modes ◽  
Framework Structure ◽  
Dynamics Calculation ◽  
The Relationship ◽  
Structural Probes

ABSTRACTWe show that the frequencies of certain optically active lattice vibrational modes in a large number of zeolites can be used as direct structural probes. Mode frequencies are found to depend on the cosine of the T-O-T angle and the Si/Al ratio of the framework. The relationship between mode frequency and local framework structure is discussed in terms of a complete lattice dynamics calculation for specific zeolite structures as well as a lattice dynamical model of amorphous glasses.

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