Deep-ultraviolet(deep-UV λ:<200 nm)zero-order waveplate crystal materials are currently scarce but much-needed.The exploration of promising deep-UV zero-order waveplate materials is extremely difficult because of ...Deep-ultraviolet(deep-UV λ:<200 nm)zero-order waveplate crystal materials are currently scarce but much-needed.The exploration of promising deep-UV zero-order waveplate materials is extremely difficult because of strict building unit and structural framework requirements.Herein,the first polyfluoroberyllophosphate crystal,Na_(4)Be_(2)PO_(4)F_(5),with a zero-dimensional(0D)structure was rationally designed and synthesized through facile hydrothermal technology.Na_(4)Be_(2)PO_(4)F_(5) features a novel[Be_(4)P_(2)O_(8)F_(10)]hexameric isolated group possessing three kinds of building units:BeO_(2)F_(2),BeOF_(3),and PO_(4).For comparison,the newly-synthesized mono-fluoroberyllophosphate crystal KBe[PO_(3)(OH)]F features a_(∞)^(1)[BePO_(3)(OH)F]chain composed of BeO_(3)F and PO_(3)(OH)building units.Na_(4)Be_(2)PO_(4)F_(5),with deep-UV transmission below 190 nm,exhibits more suitable birefringence of 0.003 at 1064 nm to act as a promising deep-UV zero-order waveplate material compared to the deep-UV crystal KBe[PO_(3)(OH)]F,which shows remarkably-enlarged birefringence of 0.025;the birefringence difference is mainly attributed to the different polarizabilities and stacking densities of the building units.Further,a systematic investigation into alkali beryllophosphates demonstrates that BeO_(4) and PO_(4) tetrahedra show a unique interconnection mode,and the 0D structure of Na_(4)Be_(2)PO_(4)F_(5),caused by the cut-off effect of F atoms,is the optimal choice for deep-UV zero-order waveplate materials.展开更多
基金supported by the NSFC(Grant 21971155,21871167)1331 project of Shanxi.
文摘Deep-ultraviolet(deep-UV λ:<200 nm)zero-order waveplate crystal materials are currently scarce but much-needed.The exploration of promising deep-UV zero-order waveplate materials is extremely difficult because of strict building unit and structural framework requirements.Herein,the first polyfluoroberyllophosphate crystal,Na_(4)Be_(2)PO_(4)F_(5),with a zero-dimensional(0D)structure was rationally designed and synthesized through facile hydrothermal technology.Na_(4)Be_(2)PO_(4)F_(5) features a novel[Be_(4)P_(2)O_(8)F_(10)]hexameric isolated group possessing three kinds of building units:BeO_(2)F_(2),BeOF_(3),and PO_(4).For comparison,the newly-synthesized mono-fluoroberyllophosphate crystal KBe[PO_(3)(OH)]F features a_(∞)^(1)[BePO_(3)(OH)F]chain composed of BeO_(3)F and PO_(3)(OH)building units.Na_(4)Be_(2)PO_(4)F_(5),with deep-UV transmission below 190 nm,exhibits more suitable birefringence of 0.003 at 1064 nm to act as a promising deep-UV zero-order waveplate material compared to the deep-UV crystal KBe[PO_(3)(OH)]F,which shows remarkably-enlarged birefringence of 0.025;the birefringence difference is mainly attributed to the different polarizabilities and stacking densities of the building units.Further,a systematic investigation into alkali beryllophosphates demonstrates that BeO_(4) and PO_(4) tetrahedra show a unique interconnection mode,and the 0D structure of Na_(4)Be_(2)PO_(4)F_(5),caused by the cut-off effect of F atoms,is the optimal choice for deep-UV zero-order waveplate materials.
