Low-temperature molten salt synthesis of ultrafine high-entropy rare-earth silicate powders

Synthesis of ultrafine powders of high-entropy rare-earth silicates (HERESs) is critical for expanding their applications. Here, we report the synthesis of ultrafine HERES powders via a simple molten salt method for the first time. The results show that the single-phase high-entropy rare-earth disilicates (HEREDs) and monosilicates (HEREMs) with monoclinic crystal structures can be successfully synthesized at 1073 and 1173 K, with the content ratios of raw rare-earth oxides to SiO2 of 1:2.4 and 1:0.9, respectively. The average particle sizes of the as-synthesized HEREDs and HEREMs powders are measured to be 1.32 and 1.64 mu m, respectively. Meanwhile, uniform elemental distributions are confirmed in these powders without any element separation or segregation. In addition, a dissolution-precipitation mechanism is proposed to clarify the synthesis process of HERESs. This study not only provides a new synthesis methodology for HERES powders but also reveals a new insight into the growth mode for HERES powders.

Automated summary

This study reports the synthesis of ultrafine powders of high-entropy rare-earth silicates (HERESs) via a simple molten salt method. The results show successful synthesis of high-entropy rare-earth disilicates (HEREDs) and monosilicates (HEREMs) with uniform elemental distribution.