Ba2Bi2[Zn(PO4)4]: ionic-isolation-activated first barium bismuth zincophosphate with unprecedented ∞[Zn(PO4)4]10− chains and balanced overall performance

Abstract

Exploration of ultraviolet phosphates with balanced overall performance is of great significance and difficulty. Herein, the first barium bismuth zincophosphate, Ba₂Bi₂[Zn(PO₄)₄], was rationally obtained by ion mixing and anionic condensation, while single crystals of Ba₂Bi₂[Zn(PO₄)₄] were synthesized by a high temperature molten salt method. In the strucutre of Ba₂Bi₂[Zn(PO₄)₄], unprecedented _∞[Zn(PO₄)₄]¹⁰⁻ chains, which were made up through the condensation of infrequent [Zn(PO₄)₅]¹³⁻ groups, were ionically bridged by massive Ba²⁺ and Bi³⁺. Having benefitted from its unique one-dimensional anionic frame and the ultilization of mutiple ions, Ba₂Bi₂[Zn(PO₄)₄] was characterized by a balanced overall performance over birefrigence, band gap and physicochemical stability. Especially, Ba₂Bi₂[Zn(PO₄)₄] was verified as a congruently melting crystal with a high melting point of about 965 °C, being conducive to practical applications.