A novel high-entropy rare-earth hydroxycarbonate synthesized via facile hydrothermal synthesis with superior decomposition temperature

This study presents for the first time the synthesis of a novel high-entropy rare-earth hydroxycarbonate, specifically (Sm₀.₂La₀.₂Y₀.₂Nd₀.₂Gd₀.₂)(CO3)OH, by using a simple hydrothermal treatment. The resulting rare-earth hydroxycarbonate exhibits superior thermal stability compared to the related single-component rare-earth hydroxycarbonates, and a distinctive rod-like morphology, maintained even after prolonged calcination (i.e. 800 ◦C for 12 h), suggesting its potential as a “sacrificial template” for high-entropy bixbyite-structured oxides. Thus, our pioneering work opens new possibilities for the application of a novel class of high-entropy hydroxycarbonates in the field of catalysis, luminescence, and sensing technologies.