The synthesis of novel lanthanum hydroxyborate at extreme conditions

Olga Ibragimova; Lia Vaquero; Zain Hussein; Vadym Drozd; Stella Chariton; Vitali Prakapenka; Irina Chuvashova

doi:10.3389/fchem.2023.1259000

The synthesis of novel lanthanum hydroxyborate at extreme conditions

Front Chem. 2023 Sep 28:11:1259000. doi: 10.3389/fchem.2023.1259000. eCollection 2023.

Authors

Olga Ibragimova¹, Lia Vaquero¹, Zain Hussein², Vadym Drozd³, Stella Chariton⁴, Vitali Prakapenka⁴, Irina Chuvashova^{1

2}

Affiliations

¹ Department of Chemistry and Biochemistry, Florida International University, Miami, FL, United States.
² Physics Department, Florida International University, Miami, FL, United States.
³ Department of Mechanical and Materials Engineering, Florida International University, Miami, FL, United States.
⁴ Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL, United States.

Abstract

The novel structure of lanthanum hydroxyborate La₂B₂O₅(OH)₂ was synthesized by the reaction of partially hydrolyzed lanthanum and boron oxide in a diamond anvil cell under high-pressure/high-temperature (HPHT) conditions of 30 GPa and ∼2,400 K. The single-crystal X-ray structure determination of the lanthanum hydroxyborate revealed: $P \bar{3} c 1$ , a = 6.555(2) Å, c = 17.485(8) Å, Z = 6, R₁ = 0.056. The three-dimensional structure consists of discrete planar BO₃ groups and three crystallographically different La ions: one is surrounded by 9, one by 10, and one by 12 oxygen anions. The band gap was estimated using ab initio calculations to be 4.64 eV at ambient pressure and 5.26 eV at 30 GPa. The current work describes the novel HPHT lanthanum hydroxyborate with potential application as a deep-ultraviolet birefringent material.

Keywords: birefringence; diamond anvil cell; high pressure; high temperature; lanthanum borate; new compound; rare-earth borates; synthesis.

Grants and funding

The authors declare financial support was received for the research, authorship, and/or publication of this article. Funding was provided by Florida International University.