Thermal Stability of GaN Investigated by Raman Scattering

Low temperature phase of YbPd investigated by Raman scattering

The possibility of the structural change in YbPd has been investigated by Raman scattering in the temperature range from 4 K to 300 K. One peak was clearly observed around 91 cm−1 below 132 K. This is a clear evidence of a structural change at the transition temperature 132 K from the CsCl structure. The polarization dependence of the 91 cm−1 peak shows that the cubic and tetragonal symmetries ...

Influence of polarity on GaN thermal stability

A comparative study of the stability of Gaand N-polar GaN films was made in different gas ambients (N2, H2, NH3, HCl). The Ga-polar films were observed to undergo a dissociative sublimation, while the N-polar films formed condensed Ga in addition to the gaseous species. The difference in polarity affects the morphology and bonding on the surface, and thus, stability of the atoms bonded to the s...

‏‎suppression of coke formation in thermal cracking by coke inhibitors‎‏

‏‎the main purpose of this research was to:1.develop a coking model for thermal cracking of naphtha.2.study coke inhibition methods using different coke inhibitors.developing a coking model in naphtha cracking reactors requires a suitable model of the thermal cracking reactor based on a reliable kinetic model.to obtain reliable results all these models shall be solved simultaneously.for this pu...

Observation of electronic Raman scattering from Mg-doped wurtzite GaN

Phonon dispersion and Raman scattering in hexagonal GaN and AlN

We present the results of roomand low-temperature measurements of second-order Raman scattering for perfect GaN and AlN crystals as well as the Raman-scattering data for strongly disordered samples. A complete group-theory analysis of phonon symmetry throughout the Brillouin zone and symmetry behavior of phonon branches, including the analysis of critical points, has been performed. The combine...