Syntheses, Structures, and Ultraviolet Nonlinear Optical Properties of the First Fluoride-Containing d10 Metal Mixed Halides, (NH4)2Cd2Cl3F3 and (NH4)2Cd2Br3F3
- 주제어 (키워드) noncentrosymmetry , nonlinear optical materials , second-harmonic generation , fluoride-containing mixed halides , ultraviolet transparency , d10 metal mixed halide system
- 발행기관 서강대학교 일반대학원
- 지도교수 옥강민
- 발행년도 2025
- 학위수여년월 2025. 2
- 학위명 석사
- 학과 및 전공 일반대학원 화학과
- 실제 URI http://www.dcollection.net/handler/sogang/000000079402
- UCI I804:11029-000000079402
- 본문언어 영어
- 저작권 서강대학교 논문은 저작권 보호를 받습니다.
초록 (요약문)
In the search for new ultraviolet (UV) nonlinear optical (NLO) materials, two novel cadmium mixed halide compounds, (NH4)2Cd2Cl3F3 and (NH4)2Cd2Br3F3, have been successfully synthesized via hydrothermal methods. These compounds crystallize in the noncentrosymmetric (NCS) space group, R32 and are composed of distorted octahedral [CdX3F3] (X = Cl or Br) units, which extend into a 3D framework. Remarkably, both compounds demonstrate strong second-harmonic generation (SHG) efficiencies—3.0 and 8.0 times that of KH2PO4 for the Cl- and Br-containing analogs, respectively—with phase-matching behavior observed. The SHG efficiency is attributed to the highly distorted coordination environment of the polarizable d10 Cd2+ ions, with (NH4)2Cd2Br3F3 benefiting further from Br's greater polarizability. Furthermore, these compounds exhibit wide band gaps exceeding 4.2 eV, making them the first d10 metal mixed halide systems incorporating fluoride that are suitable for UV NLO applications. With UV absorption cut-off edges as short as 203 nm for (NH4)2Cd2Cl3F3 and 243 nm for (NH4)2Cd2Br3F3, these materials represent a significant advancement in the development of UV-transparent NLO materials. This study introduces a novel synthetic strategy for the design of d10 mixed halide systems with enhanced optical properties, offering promising candidates for future UV NLO technologies.
more목차
1. Abstracts 11
2. Introduction 13
3. Experimental Section 16
2.1. Syntheses 16
2.2. Measurements 17
4. Results & Discussion 25
4.1. Crystal Structures of (NH4)2Cd2Cl3F3 and (NH4)2Cd2Br3F3 25
4.2. Ultraviolet-Visible (UV-vis) Diffuse Reflectance Spectroscopy 29
4.3. Thermogravimetric Analysis (TGA) 31
4.4. Density Functional Theory (DFT) calculations 35
4.5. Powder Second-Harmonic Generation (SHG) measurements 38
5. Conclusion 45
6. References 47
