Improved Surface Crystallinity of MgO Crystal Substrate through Annealing in Oxygen Atmosphere

Abstract

We show in this paper that it is possible to induce superconducting vortices in a gold nanowire connected to superconducting electrodes. The gold nanowire acquires superconductivity by the proximity effect. The differential magnetoresistance of the nanowire beyond a critical magnetic field shows uniform oscillations with increasing field with a period of 0 /(2πr 2 ) ( 0 = h/2e is the superconducting flux quantum, r = 35 nm is the radius of the nanowire). Our analysis indicates that these periodic oscillations are the signatures of the sequential generation and moving of vortices across the gold nanowire.

Raman spectroscopy investigation of magnesium oxide nanoparticles

“…It has been reported by many authors that MgO reacts with CO 2 to form MgCO 3 . [34][35][36] We assign that peak at 1088 cm −1 to the carbonate group CO 3 2− based on the Raman spectrum of MgCO 3 (see Fig. 5), the lower frequency peaks that appear on the MgCO 3 spectrum (about 210 cm −1 and 330 cm −1 ) being too weak to appear on our spectra.…”

“…5), the lower frequency peaks that appear on the MgCO 3 spectrum (about 210 cm −1 and 330 cm −1 ) being too weak to appear on our spectra. According to literature, an annealing of 700 °C is required to desorb these ions from the surface of MgO [34][35][36] Most importantly, both peaks at 278 cm −1 and 445 cm −1 also disappear and do not spontaneously form again upon cooling when physisorption of water occurs again. This is a necessary requirement to assign these peaks to the presence of Mg(OH) 2 .…”

“…5), the lower frequency peaks that appear on the MgCO 3 spectrum (about 210 cm −1 and 330 cm −1 ) being too weak to appear on our spectra. According to literature, an annealing of 700 °C is required to desorb these ions from the surface of MgO 34–36…”

Charge transfer from Cu in YBa2Cu3O7−δ and Ba2Cu3O4Cl2 crystals determined by Auger electron spectroscopy

“…A candidate procedure would be annealing in oxygen atmosphere which, in fact has been proven to be successful in improving surface morphology for some oxides. [44][45][46] In this respect, supplemental observations of RHEED patterns would be necessary.…”

Influence of the core-hole effect on optical properties of magnesium oxide (MgO) near the MgL-edge region

“…It is regarded as one of the potential dielectric material that has ample applications in semiconductor integrated devices. It is also well known for its use as a substrate (Awaji et al, 1992) in depositing high-quality oxide films. There are several instances in the literature where MgO is regarded as a suitable material for a spacer (Fuhse et al, 2004) and protective layer in multilayer mirrors in the soft X-ray/vacuum ultraviolet (VUV) region.…”