Formation and aspect ratio control of rhabdophane-type yttrium orthophosphate hexagonal prism particles synthesized by a citrate-assisted hydrothermal process. Issue 16 (8th April 2022) - Shiba, Fumiyuki
Abstract : The rhabdophane-type YPO4 particles have been synthesized in the presence of citrate ions under systematically varied reaction conditions. Abstract : Rhabdophane-type yttrium orthophosphate particles were prepared in an aqueous phase with trisodium citrate (Na3 -Cit) under systematically varied conditions. The obtained rhabdophane-type YPO4 particles were basically in a hexagonal prism shape, reflecting its hexagonal crystal structure. The prism's width and height differed depending on the reaction conditions. A higher Na3 -Cit concentration led to a lower prism height, whereas a higher pH similarly decreased the width and height. The growth kinetics suggested that the rhabdophane-type YPO4 particles grew in the surface-reaction-controlled growth mode. The activation energies of the growth, estimated by the Arrhenius plots in the range of 95–120 °C, were slightly different between the width and the height directions, resulting in the temperature-dependent shape of the hexagonal prism. Also, Tb 3+ ions were doped into the rhabdophane-type YPO4 particles to observe photoluminescence.