Investigations on the Synthesis, Crystal Structure, Linear- and Nonlinear-Optical Properties of the Zinc Germanate Rb2ZnGe2O6

Tao Han; Conggang Li; Wenli Zhao; Yuheng She; Jinmiao Jiao; Fei Liang; Zhanggui Hu; Yicheng Wu

doi:10.1021/acs.inorgchem.1c03465

Investigations on the Synthesis, Crystal Structure, Linear- and Nonlinear-Optical Properties of the Zinc Germanate Rb₂ZnGe₂O₆

Inorg Chem. 2022 Jan 10;61(1):706-712. doi: 10.1021/acs.inorgchem.1c03465. Epub 2021 Dec 22.

Authors

Tao Han¹, Conggang Li¹, Wenli Zhao¹, Yuheng She¹, Jinmiao Jiao¹, Fei Liang², Zhanggui Hu¹, Yicheng Wu¹

Affiliations

¹ Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystal, Tianjin University of Technology, Tianjin 300384, China.
² State Key Laboratory of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan 250100, China.

PMID: 34935373
DOI: 10.1021/acs.inorgchem.1c03465

Abstract

A quaternary nonlinear-optical (NLO) zinc germanate, Rb₂ZnGe₂O₆ (RZGO), was prepared from its stoichiometric melts, which belongs to the noncentrosymmetric space group C222₁ (No. 20) and features a 3D framework formed by GeO₄ tetrahedra, ZnO₄ tetrahedra, and Rb⁺ cations filling into the void space. RZGO displays a good phase-matchable second-harmonic-generation (SHG) intensity similar to that of KH₂PO₄. The UV cutoff edge for RZGO was found to be approximately 0.37 μm with a broad optical band gap of 3.22 eV, indicating a large laser-induced damage threshold. Further characterizations suggested that this compound displays an excellent thermal stability (1014 °C) and melts congruently. Besides, theoretical analysis was also implemented to investigate the electronic structures and effective NLO coefficients as well as the origin of the observed SHG response for RZGO. The present study can enrich the diversity of acentric germanate structures and pave the way for the synthesis of new NLO compounds.