Showing papers by "Shiv Nadar University published in 1999"
TL;DR: In this paper, the authors evaluated ion-beam induced damage in α-quartz and its dynamic annealing behavior in the temperature range between 80 and 1050 K using Rutherford backscattering spectrometry in channeling geometry.
Abstract: We report on the evaluation of ion-beam induced damage in α-quartz and its dynamic annealing behavior in the temperature range between 80 and 1050 K using Rutherford backscattering spectrometry in channeling geometry. The results illustrate that the critical temperature for inhibiting amorphization during irradiation is about Tc≈940 K. The critical fluence φc for amorphization is independent of the temperature up to 550 K, but strongly increases at higher temperatures. The activation energy for the diffusion of defects in the collision cascade or at the amorphous/crystalline interface is found to be 0.28±0.02 eV. The dynamic annealing mechanism is explained by the vacancy out-diffusion model of Morehead and Crowder.
32 citations
TL;DR: In this article, first-principles calculations are carried out with the objective of assigning a chemical identity to the variety of forms of molecular oxygen which are known to exist on a TiO2(110) surface.
Abstract: First-principles calculations are carried out with the objective of assigning a chemical identity to the variety of forms of molecular oxygen which are known to exist on a TiO2(110) surface. Six different geometries and spin configurations of O2 are shown to be stable in the bridging oxygen defect site. The relationship of these results to experimental observations is discussed.
27 citations
TL;DR: In this article, the solid phase epitaxial growth of thin amorphous SiO2 films deposited by electron gun evaporation on single-crystalline α-quartz substrates was reported.
Abstract: The epitaxial α-quartz thin film could be a promising material for fabricating optical devices because of its unique optical and mechanical properties and processing advantages compared to bulk materials This letter reports on the solid-phase epitaxial growth of thin amorphous SiO2 films deposited by electron gun evaporation on single-crystalline α-quartz substrates This was achieved by high-dose Cs+-ion implantation and subsequent thermal annealing in air Also, a thin amorphous layer produced by Si+-ion implantation on α-quartz was epitaxially regrown, thus indicating that the epitaxy is independent of the preparation history of the amorphous layer The results are explained on the basis of network modifications induced by alkali and oxygen in the SiO2 structure
22 citations
TL;DR: In this article, the design, fabrication, and testing of a fractional h.p. permanent magnet synchronous motor (PMSM) are reported, where the stator has been fitted with a balanced three-phase mush winding.
Abstract: The design, fabrication, and testing of a fractional h.p. permanent magnet synchronous motor (PMSM) are reported in this paper. The stator has been fitted with a balanced three-phase mush winding. Moreover, the performance analysis using Maxwell Field Simulator has been included. The test results of the motor with a fan load confirms the satisfactory operation of the machine designed in this paper.
3 citations
1 citations