Showing 3 results for Ftir
Prof. Rasoul Malekfar, Mr. Akbar Cheraghi,
Volume 8, Issue 1 (1-2014)
Abstract
Nanocrystallite α-cordierite glass-ceramics are synthesized using a modified Pechini method. The structural and lattice modes of the products are investigated via XRD and Micro Raman back-scattering spectroscopy. The Debye-Scherrer formula is used to confirm the grain sizes estimated by the SEM slides. Dielectric coefficients calculation and DTA analysis are used to study the synthesized nanocrystallites properties.
Prof. Rasoul Malekfar, Ms. Marziye Parishani, Mr. Akbar Cheraghi,
Volume 9, Issue 2 (11-2015)
Abstract
Ni ferrite crystalline material is synthesized using a sol-gel method at two different temperatures. The vibrational and stretching modes, crystalline phase, size distribution and morphology of the products are investigated via Raman back-scattering and Fourier transform infrared (FTIR) spectroscopy, XRD and FESEM, respectively. Vibrational modes of spinel ferrite are observed at Raman and FTIR spectra. Group theory phonon analysis reveals five Raman active modes for the molecular system. However, in the present investigation, four Raman modes are identified in the inelastic Stokes region of the recorded Raman scattering spectra. Also, the results of the present study reveals that the sizes of the synthesized particles were increased and crystalline structures were completed by increasing the temperature.
Dr. Mohammad Hossein Hekmatshoar, Ms. Samira Vafaei,
Volume 10, Issue 2 (11-2016)
Abstract
Glassy samples with a composition of 40P2O5–30V2O5–(30-x)Li2O– xK2O, 0<x<30 (mol %) were prepared by the conventional melt quenching technique in two forms of bulk and blown film. X-ray diffraction patterns corroborated the amorphous feature of the samples. Density of samples was investigated by using Archimedes principle. Based on absorption and reflection spectra, indirect allowed optical gaps, Urbach energies, refractive index and dielectric coefficients were calculated. Study of FTIR spectra revealed that all of the samples mainly contain metaphosphate and pyrophosphate units. Glass transition temperatures were also evaluated using DSC curves. Non-linear variation of many physical properties by gradually substitution of Li ions with K, confirmed the existence of mixed alkali effect in glassy system.