Abu El-Fadl, A. and Nashaat, A.M. (BSP-TOOPTSJ-2015-25) Temperature Dependence of the Optical Band Gap and Optical Parameters of Tetramethyl Ammonium Tetrachlorozincate (TMA)₂ZnCl₄ Single Crystals around the Normal and Incommensurate Phase Transitions. Paper Submitted for Publications in Journal of Modern Optics.

has been cited by the following article:

• TITLE: Optical Characterization of (TMA)2ZnCl4 Single Crystals in the Normal Phase

  AUTHORS: A. Abu El-Fadl, M. Almokhtar, A. M. Nashaat

  KEYWORDS: (TMA)2ZnCl4 Single Crystals, Optical Band Gap, Refractive Index, Dispersion Parameters, FTIR Spectroscopy

  JOURNAL NAME: Open Journal of Applied Sciences, Vol.5 No.4, April 24, 2015

  ABSTRACT: The transmittance (T) and the reflectance (R) were measured for (TMA)2ZnCl4 single crystals and hence the absorption coefficient (α), extinction coefficient (Kex.), refractive index (n), real and im-aginary dielectric constants (ε', ε") of (TMA)2ZnCl4 crystals were calculated as a function of photon energy. The analysis of the spectra behavior of the absorption coefficient in the absorption region revealed indirect transition. The dispersion of the refractive index is discussed in terms of the sin-gle oscillator Wemple-DiDomenico model. The single oscillator energy (E0), the dispersion energy (Ed), the lattice dielectric constant (εL) and the ratio of free charge carrier concentration to the ef-fective mass (N/m*) were estimated. The FTIR spectra were recorded to study the functional groups of the as grown and annealed samples.