Pressure and Temperature Derivatives of the Low-Frequency Dielectric Constants of LiF, NaF, NaCl, NaBr, KCl, and KBr

1972 ◽  
Vol 6 (2) ◽  
pp. 582-590 ◽  
Author(s):  
John Fontanella ◽  
Carl Andeen ◽  
Donald Schuele
Keyword(s):  
Low Frequency ◽  
Dielectric Constants ◽  
Derivatives Of

DERIVATIVES OF MONOGERMANE: PART I. THE VIBRATION–ROTATION SPECTRA OF GERMYL FLUORIDE AND BROMIDE

1962 ◽  
Vol 40 (4) ◽  
pp. 579-589 ◽  
Author(s):  
J. E. Griffiths ◽  
T. N. Srivastava ◽  
M. Onyszchuk
Keyword(s):  
Harmonic Oscillator ◽  
Infrared Absorption ◽  
Thermodynamic Functions ◽  
Low Frequency ◽  
Rotational Constant ◽  
Rigid Rotator ◽  
Harmonic Oscillator Model ◽  
Infrared Absorption Spectra ◽  
Vibration Rotation ◽  
Derivatives Of

The vibration–rotation infrared absorption spectra of germyl fluoride and bromide have been observed. All of the fundamentals in GeH3F were located, and the rotational structure of the E-type bands were resolved and analyzed. The low-frequency band, ν3(a1), in GeH3Br was not observed but an estimate of its position was made from the frequencies of the combination band ν3 + ν6 and of ν6. The rotational constant A″ and the Coriolis constants ζ4, ζ5, and ζ6 were calculated for both molecules, and agreement with microwave A″ values was satisfactory. Thermodynamic functions based upon a rigid-rotator, harmonic-oscillator model have been evaluated for germyl fluoride and bromide.

Photoelastic behaviour and interionic potentials in alkali halide crystals

1981 ◽  
Vol 59 (10) ◽  
pp. 1359-1366 ◽  
Author(s):  
Jai Shanker ◽  
T. S. Verma ◽  
A. Cox ◽  
M. J. L. Sangster
Keyword(s):  
Shell Model ◽  
High Frequency ◽  
Alkali Halide ◽  
Dielectric Constants ◽  
Critical Test ◽  
Photoelastic Data ◽  
Comparison Of The Results ◽  
Alkali Halide Crystals ◽  
Derivatives Of ◽  
Photoelastic Behaviour

In order to make a critical test of some recently developed interionic potentials based on the shell model, the photoelastic behaviour of the alkali halide crystals has been investigated. Values of the strain derivatives of the static and high-frequency dielectric constants have been calculated from sets of potentials due to Catlow et al., Sangster et al., and Sangster and Atwood. A comparison of the results obtained with available experimental photoelastic data demonstrates the superiority of the second set of potentials of Catlow et al.

scholarly journals Dielectric Constants of a Binary Solution Near the Critical Solution Temperature

1973 ◽  
Vol 51 (4) ◽  
pp. 545-550 ◽  
Author(s):  
I. Lubezky ◽  
R. McIntosh
Keyword(s):  
High Frequency ◽  
Binary Solution ◽  
Critical Concentration ◽  
Low Frequency ◽  
Dielectric Constants ◽  
Solution Temperature ◽  
Dielectric Losses ◽  
Theoretical Studies ◽  
Critical Solution Temperature ◽  
Experimental Knowledge

The dielectric constants and dielectric losses of solutions of nitrobenzene and 2,2,4-trimethyl pentane have been measured near the critical solution temperature over a concentration range of 22–75% by weight and in the frequency regions of 5–60 and 1000 – 4000 kHz. It was found that below a critical concentration of 35% maxima existed in ε′ and ε″ at a temperature of 0.3 °C above the critical solution temperature. At higher concentrations the maxima disappeared and phase separation was preceded only by changes in the thermal coefficients dε′/dT and dε″/dT. The present study combined with others indicates that two regions of loss exist for the system near the critical temperature: low frequency losses of a conductive nature and high frequency losses of the Debye type. The published experimental knowledge of such systems remains insufficient to enable a thorough test of the theoretical studies published recently by Snider.

Calculations of the Spontaneous Polarizations and Dielectric Constants for AlN, GaN, InN, and SiC

2010 ◽  
Vol 645-648 ◽  
pp. 1203-1206
Author(s):  
Sergey Y. Davydov ◽  
Alexander A. Lebedev
Keyword(s):  
Experimental Data ◽  
Ab Initio ◽  
Spontaneous Polarization ◽  
Reasonable Agreement ◽  
Low Frequency ◽  
Analytical Form ◽  
Dielectric Constants ◽  
Numerical Calculations ◽  
Ab Initio Methods ◽  
Theoretical Results

Within the scope of the Harrison’s bond orbital model the spontaneous polarization, high- and low frequency dielectric constants are obtained in an analytical form. Theoretical results are in a reasonable agreement with the experimental data available and the numerical calculations based on the ab initio methods.

Sign in / Sign up

Export Citation Format

Share Document