Characterization of ZnWO₄, MgWO₄, and CaWO₄ Ceramics Synthesized in the Field of a Powerful Radiation Flux

Abstract

This paper presents the results of a study on the morphology, structure, and luminescent properties of ceramics synthesized in the radiation field of MeWO4 compositions (where Me is Mg, Ca, and Zn). The synthesis of ceramics was carried out by the direct action of the electron flux on an initial mixture of powders of the given stoichiometric composition. WO3, ZnO, MgO, and CaO powders with particle sizes in the range of 1–50 microns were used for the synthesis of the samples. It was found that the yield of the radiation synthesis reaction (the ratio of the mass of the sample and the charge used), when treated with an electron flux with an energy of 1.4 MeV and a flux power density of 15–18 kW/cm2, was in the range of 75–99%. The synthesis of all compositions was carried out under the same radiation treatment modes, although the melting temperatures of the starting materials varied significantly and ranged from 1473 °C (WO3) to 2825 °C (MgO). The study of the ceramic structure showed that under the radiation effect of powerful radiation fluxes on the charge, a crystalline phase of the appropriate composition formed, regardless of the synthesis modes. The results of XRD studies show that during the radiation treatment of the charge, ceramics are formed mainly with the crystalline phases ZnWO4, MgWO4, and CaWO4. These resulting MeWO4 ceramics can be used for the same purposes as crystals. Photoluminescence (PL) and cathodoluminescence (CL) were studied under excitation using stationary ultraviolet radiation and nanosecond pulses of electron flux. In general, the PL and CL of synthesized ceramic samples ZnWO4, MgWO4, and CaWO4 showed that their luminescent properties are similar to those of luminescence in corresponding crystalline materials. This indicates the formation of a crystalline phase in synthesized ceramic samples.

Keywords

• ceramic
• metal tungstate
• radiation synthesis
• electron flux
• cathodoluminescence
• photoluminescence