Wu, TianhuiJiang, XingxingWu, ChaoSha, HongyuanWang, ZujianLin, ZheshuaiHuang, ZhipengLong, XifaHumphrey, MarkZhang, Chi2024-03-142024-03-142050-7534http://hdl.handle.net/1885/315995Efficient mid-infrared (mid-IR) nonlinear optical (NLO) crystals are highly desirable, but it remains extremely challenging to simultaneously achieve a strong second harmonic generation (SHG) response, a large optical bandgap, and wide optical transparency in a material. In this work, a fluorinated homovalent substitution strategy has been put forward and this strategy leads to a new cerium fluorinated iodate, CeF2(IO3)(2), which is designed based on a noncentrosymmetric cerium iodate, Ce(IO3)(4). The introduction of F- ions enables CeF2(IO3)(2) to achieve the simultaneous enhancement of an enlarged phase-matchable SHG response that is 8 times that of KH2PO4 (KDP) and a bandgap of 2.90 eV compared to its parent Ce(IO3)(4) (0.9x KDP and 2.17 eV, respectively). CeF2(IO3)(2) exhibits a high thermal stability (similar to 430 degrees C) and a wide transparent region (0.43-6.46 mu m), suggesting that CeF2(IO3)(2) is a promising mid-IR NLO material. First-principles simulations reveal that the difference in linear and nonlinear optical properties between Ce(IO3)(4) and CeF2(IO3)(2) is mainly attributed to the divergent anisotropies of the cerium-centered polyhedra.The authors acknowledge the UK’s Science and Technology Facilities Council (STFC) for access to the PEARL instrument, and for funding this researchapplication/pdfen-AUThis journal is © The Royal Society of Chemistry 2024https://creativecommons.org/licenses/by-nc/3.0/202110.1039/d1tc01883c2022-11-13Creative Commons Attribution-NonCommercial 3.0 Unported Licence