Yuan Feifei, Hu Lei, Bai Zhiyong, Liu Lehui, Huang Yisheng, Zhang Lizhen, Wei Dongshan, Lin Zhoubin
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China.
Inorg Chem. 2021 Jun 7;60(11):8103-8110. doi: 10.1021/acs.inorgchem.1c00521. Epub 2021 May 24.
Deep-ultraviolet (DUV) nonlinear optical (NLO) materials play vital roles in diverse fields. Unfortunately, only the KBeBOF crystal has found commercial applications so far. Therefore, the discovery of new DUV NLO crystals is still urgent. As we all know, digging into the properties of existing crystals is also an effective way to obtain new NLO crystals. Herein, two natural asymmetric orthophosphates AMgPO·6HO (A = NH, K) are proposed. Although their structures and some properties such as infrared spectra, thermal properties, and dielectric properties have been previously characterized, their NLO properties have not been reported. Thus, in this work, these two natural DUV transparent orthophosphates NHMgPO·6HO (NMP) and KMgPO·6HO (KMP) were successfully acquired by a simple slow evaporation method. The single-crystal X-ray diffraction data indicate that NMP and KMP are isomorphic and that both belong to the 2 space group of the orthorhombic system. Remarkably, NMP and KMP possess short cutoff edges below 190 nm, and their second-harmonic generation (SHG) efficiencies are 0.62 and 0.80 times that of KHPO(KDP), respectively; furthermore, they can achieve type-I phase matching at 1064 nm.
深紫外（DUV）非线性光学（NLO）材料在众多领域发挥着至关重要的作用。遗憾的是，迄今为止只有KBeBOF晶体获得了商业应用。因此，发现新型深紫外非线性光学晶体仍然迫在眉睫。众所周知，深入研究现有晶体的性质也是获得新型非线性光学晶体的有效途径。在此，我们提出了两种天然不对称正磷酸盐AMgPO₄·6H₂O（A = NH₄⁺，K⁺）。尽管它们的结构以及一些性质，如红外光谱、热性质和介电性质此前已被表征，但其非线性光学性质尚未见报道。因此，在本工作中，通过简单的缓慢蒸发法成功获得了这两种天然的深紫外透明正磷酸盐NH₄MgPO₄·6H₂O（NMP）和KMgPO₄·6H₂O（KMP）。单晶X射线衍射数据表明NMP和KMP是同构的，且二者均属于正交晶系的2空间群。值得注意的是，NMP和KMP具有低于190 nm的短截止边，其二次谐波产生（SHG）效率分别是磷酸二氢钾（KDP）的0.62倍和0.80倍；此外，它们在1064 nm处可实现I型相位匹配。
