Three new complex borate compounds K7CaBi2B15O30, K7CaLa2B15 O30 and K7BaBi2B15O30 have been synthesized by the high-temperature solution method.K7CaLa2B15O30and K7CaBi2B15O30crystallize in the chiral trigonal space g...Three new complex borate compounds K7CaBi2B15O30, K7CaLa2B15 O30 and K7BaBi2B15O30 have been synthesized by the high-temperature solution method.K7CaLa2B15O30and K7CaBi2B15O30crystallize in the chiral trigonal space group R32, while K7BaBi2B15O30 crystallizes in the noncentrosymmetric orthorhombic polar space group Pca21. All of the title compounds have similar three-dimensional crystal structures, which are composed of isolated B5 O10 groups and LaO6 or BiO6 octahedra, and K^+, Ca^2+, and Ba^2+ cations fill into the cavities to keep charge balance. Based on our research, in the system of K7 MIIRE2 B15O30(MII= Ca, Sr,Ba, Zn, Cd, Pb, K/RE0.5;RE = Sc, Y, La, Gd, Lu, Bi),K7BaBi2B15O30 is unique and crystallizes in a different space group, which enriches the structural chemistry of borate.Detailed structural analyses indicate that the structural variation is due to the difference in size and coordination number of the alkaline-earth metal cations. Besides, UV-Vis-NIR spectroscopy analysis and the second-harmonic generation(SHG) measurement on the powder samples show that K7CaBi2B15O30 exhibits a UV cutoff edge(about 282 nm) and a moderate SHG response(about 0.6 × KDP). In addition,thermal analysis and infrared spectroscopy were also presented. To better understand the structure-property relationships of the title compounds, the first-principles calculations have been performed.展开更多
基金supported by the West Light Foundation of the CAS(2016-YJRC-2 and 2015 XBQN-B-11)the National Natural Science Foundation of China(51602341 and 91622107)+2 种基金the Natural Science Foundation of Xinjiang(2016D01B061)Tianshan Innovation Team Program(2018D14001)Key research project of Frontier Science of CAS(QYZDB-SSW-JSC049)
文摘Three new complex borate compounds K7CaBi2B15O30, K7CaLa2B15 O30 and K7BaBi2B15O30 have been synthesized by the high-temperature solution method.K7CaLa2B15O30and K7CaBi2B15O30crystallize in the chiral trigonal space group R32, while K7BaBi2B15O30 crystallizes in the noncentrosymmetric orthorhombic polar space group Pca21. All of the title compounds have similar three-dimensional crystal structures, which are composed of isolated B5 O10 groups and LaO6 or BiO6 octahedra, and K^+, Ca^2+, and Ba^2+ cations fill into the cavities to keep charge balance. Based on our research, in the system of K7 MIIRE2 B15O30(MII= Ca, Sr,Ba, Zn, Cd, Pb, K/RE0.5;RE = Sc, Y, La, Gd, Lu, Bi),K7BaBi2B15O30 is unique and crystallizes in a different space group, which enriches the structural chemistry of borate.Detailed structural analyses indicate that the structural variation is due to the difference in size and coordination number of the alkaline-earth metal cations. Besides, UV-Vis-NIR spectroscopy analysis and the second-harmonic generation(SHG) measurement on the powder samples show that K7CaBi2B15O30 exhibits a UV cutoff edge(about 282 nm) and a moderate SHG response(about 0.6 × KDP). In addition,thermal analysis and infrared spectroscopy were also presented. To better understand the structure-property relationships of the title compounds, the first-principles calculations have been performed.
