Growth and optical properties of transition metal oxides single crystal solid solutions
Abstract NiO, CoO, MnO single crystals and single crystal solid solutions of Ni c Mg 1− c O, Co c Mg 1− c O and Mn c Mg 1− c O were grown by the method of chemical transport reaction (the “sandwich” technique). The nature of the observed absorption and luminescence bands is explained in terms of the electronic transition of bivalent nickel, cobalt and manganese. The fine structure of the observed bands in NiO and MnO are connected to the pure exciton transition and to the exciton-magnon excitation.
The eighth-order perturbation formula for the EPR cubic zero-field splitting parameter of d5(6S) ion and its applications to MgO:Mn2+ and MnCl2.2H2O
The eighth-order perturbation formula for the EPR cubic field splitting parameter alpha has been obtained by taking a cubic crystal field and the spin-orbit interaction as the perturbation Hamiltonian. In the calculation, not only spin quartet states but also spin doublet states have been considered. The calculated result shows that the contributions of the double states and eighth-order perturbation cannot be neglected. For MgO:Mn2+ and MnCl2.2H2O, the d-d transitions and the cubic zero-field splitting parameter have been calculated by using Zhao's self-consistent-field (SCF) orbital for the Mn2+ ion and the high-order perturbation formula for the cubic zero-field splitting parameter have been obtained. The results of applications agree well with experiments.
Physical Ageing of the Research Reactor Core Structural Materials Due to Neutron Irradiation Exposure: a Review
A research reactor (RR) is a  nuclear reactor that has function to generate and utilize neutron flux and radiation ionization for  research purposes and industrial applications. More than 60% of current operating RRs have  been operated for 30 years or more. As the time passes, the functional capabilities of structures,  systems and components (SSCs) of those RRs deteriorate by physical ageing, which can be  caused by neutron irradiation exposure such as irradiation induced dislocation and  microstructural changes. To extend the lifetime and/or to avoid unplanned outages, ageing on  the safety related SSCs of RRs need to be properly managed. An ageing management is a  strategy to engineer, operate, maintenance, and control SSC degradation within acceptable limits. The purpose of this study is to review physical ageing of the core structural materials of  the RRs caused by neutron irradiation exposure. In order to achieve this objective, a wide range  of literatures are reviewed. Comprehensive discussions on irradiation behaviors are limited only  on reactor vessel and core support structure materials made from zirconium and beryllium as  well as their alloys, which are widely used in RRs. It is found that the stability of the mechanical  properties of zirconium and beryllium as well as their alloys was mostly affected by the neutron  fluences and temperatures.