Optical spectroscopy study of damage evolution in 6H-SiC by H_(2)^(+)implantation

Lattice defects induced by ion implantation into SiC have been widely investigated in the decades by various techniques.One of the non-destructive techniques suitable to study the lattice defects in SiC is the optical characterization.In this work,confocal Raman scattering spectroscopy and photoluminescence spectrum have been used to study the effects of 134-keV H_(2)^(+)implantation and thermal treatment in the microstructure of 6H-SiC single crystal.The radiation-induced changes in the microstructure were assessed by integrating Raman-scattering peaks intensity and considering the asymmetry of Raman-scattering peaks.The integrated intensities of Raman scattering spectroscopy and photoluminescence spectrum decrease with increasing the fluence.The recovery of the optical intensities depends on the combination of the implantation temperature and the annealing temperature with the thermal treatment from 700℃to 1100℃.The different characterizations of Raman scattering spectroscopy and photoluminescence spectrum are compared and discussed in this study.

A review of solute-point defect interactions in vanadium and its alloys: first-principles modeling and simulation

Vanadium alloys are the promising first wall and blanket materials for fusion reactors.Large amounts of helium(He)and hydrogen(H)impurities are produced inside the materials along with irradiation defects under neutron irradiation,leading to bubble formation and microstructure changes,which will degrade the thermal and mechanical properties of vanadium alloys.The microstructure changes of materials are influenced by the interactions of point defects with solute atoms.Nowadays,first-principles calculations are intensively performed to elucidate these interactions,clustering,and dissolution,which can provide valuable information for the design of high-performance anti-irradiation materials.This paper reviews the recent findings of the interactions of point defects(vacancies,self-interstitial atoms)with substitutional solutes and interstitial solutes(C,O,N,H,and He)as well as their clusters in vanadium and its alloys from first-principles calculations.