A Deep-UV Nonlinear Optical Borosulfate with Incommensurate Modulations.

Area of Science:

• Solid-state chemistry
• Materials science
• Crystallography

Background:

• Borate-sulfates with isolated groups are known, but borosulfates with B-O-S bonding are rare.
• Properties of borosulfates with B-O-S bonding remain underexplored.

Purpose of the Study:

• Report the synthesis and properties of a new borosulfate, LiRb4[B(SO4)4].
• Investigate its potential as a deep-ultraviolet nonlinear optical (NLO) material.
• Explore its structural phase transitions and modulations.

Main Methods:

• In situ single-crystal X-ray diffraction to study phase transitions.
• First-principle calculations to analyze structure-property relationships.
• Structural analysis of [B(SO4)4]5- super-tetrahedral units.

Main Results:

• LiRb4[B(SO4)4] exhibits potential as a novel deep-UV NLO material.
• Successive first-order phase transitions with incommensurate modulations were observed.
• NLO properties and phase transitions are linked to the [B(SO4)4]5- units with B-O-S bonding.

Conclusions:

• The new borosulfate LiRb4[B(SO4)4] presents a unique combination of deep-UV transparency, NLO responses, and incommensurate structural modulations.
• This material offers new avenues for understanding physics and chemistry in aperiodic materials.