Different p-block elements induce C₃[111] octahedral distortion in titanium to generate an intense nonlinear effect

Area of Science:

• Inorganic Chemistry
• Materials Science
• Solid-State Chemistry

Background:

• Acentric crystalline materials are crucial for advanced technologies but challenging to synthesize.
• Existing methods for creating acentric materials often face limitations in controllability and efficiency.

Purpose of the Study:

• To synthesize a novel acentric tellurite sulfate, Ti(TeO3)(SO4), by modifying a centric d0 transition metal matrix.
• To investigate the structural features responsible for the material's nonlinear optical properties.
• To explore the potential of this new material in nonlinear optics.

Main Methods:

• Synthesized a novel acentric material, Ti(TeO3)(SO4), by introducing a p-block element into TiTe3O8.
• Analyzed the crystal structure, focusing on the distortion of the [TiO6] octahedron induced by [TeO3] and [SO4] groups.
• Measured the second harmonic generation (SHG) response and birefringence of the synthesized material.

Main Results:

• Successfully constructed the novel acentric tellurite sulfate Ti(TeO3)(SO4).
• Observed significant out-of-center distortion in the [TiO6] octahedron due to the presence of lone-pair [TeO3] and rigid [SO4] groups.
• Achieved a strong second harmonic generation (SHG) response of 11.6 × KDP, the highest among mercury-free sulfates.
• Exhibited the largest birefringence (0.145) among sulfates with SHG responses exceeding 10 × KDP.

Conclusions:

• The strategy of inducing intra-octahedral distortion in d0 transition metals using p-block elements is effective for creating acentric structures.
• Ti(TeO3)(SO4) demonstrates exceptional nonlinear optical properties, positioning it as a promising candidate for advanced optical applications.
• This work opens new avenues for designing and synthesizing acentric sulfates with superior nonlinear optical performance.