SYNTHESIS, STRUCTURE, LUMINESCENT AND MECHANICAL PROPERTIES OF YNb х Ta 1 –х O 4 SOLID SOLUTIONS

A series of mixed yttrium tantalo-niobates (YNb х Ta 1– х O 4 , x = 0-1) is obtained by the sol-gel synthesis. It is shown that the temperature of this synthesis of YNb х Ta 1– х O 4 and its duration are much lower than those in the solid-phase synthesis. The properties of both synthesized powders and ceramic solid solutions (SSs) YNb х Ta 1– х O 4 , x = 0-1, prepared based on them, are investigated. It is found that under UV excitation at any Nb:Ta ratio in YNb х Ta 1– х O 4 SSs the luminescent signal is enhanced as compared to that in individual YNbO 4 and YTaO 4 compounds, which is caused by energy transfer between the Nb 4+ –O – and Ta 4+ –O – luminescence centers. Morphological features of the microstructure of ceramic YNb х Ta 1– х O 4 SSs are studied. Mechanical characteristics of ceramic YNb х Ta 1– х O 4 SSs, such as Young’s modulus and the stress intensity factor for mode 1 K IC , which is a criterion of the material crack resistance, are estimated.