Topical trends in the application of rare-earth metals and their compounds in the production of magnetic and luminescent materials

Abstract

This review is devoted to the review of current trends in the use of rare-earth metals (REM) in two major scientific and technical fields – the production of magnetic and luminescent materials. The reviews show that it is REM that gives this product unique properties. The information on the content of matrix and alloying components, their influence on achieving the required characteristics of the most popular magnetic materials is systematized. The prospects of new combinations of rare-earth metals in the further progress of the production of magnetic materials for various purposes are shown. Along with the traditional cobalt-samarium and neodymium-iron-boron compositions, new magnetic materials with increased hysteresis properties and temperature-time stability have been developed, phases with variable valence have been synthesized, which are used as memory elements in information systems. The article also reviews and summarizes the results of studies in another important area of REM application – the creation of luminescent materials. Phosphors based on compounds of rare earth metals are used in the production of high-pressure mercury lamps with improved characteristics, X-ray screens, high and low pressure fluorescent lamps, screens for electron-optical converters. Narrow-band phosphors based on REM compounds are of interest for lamps used in plant growing, especially for areas with a cold climate, where year-round plant growth is possible only with the use of additional radiation sources.The trends in the synthesis of luminescent materials using various rare-earth metals and their combinations are revealed. Attention is turned to the need to use chemically pure precursors of rare-earth metals in the creation of such materials. The prospects of creating nanophosphors, as well as the improvement of synthesis methods and diagnostic methods, are noted.