A new non-centrosymmetric Gd-based borate crystal Rb7SrGd2(B5O10)(3): growth, structure, and nonlinear optical and magnetic properties

摘要

A new non-centrosymmetric borate crystal, Rb7SrGd2(B5O10)(3), was successfully grown via the spontaneous nucleation technique from the Rb2O-B2O3-SrO self-flux system. It crystallizes in the trigonal system space group R32 with lattice parameters a = b = 13.4975(5) angstrom,c = 15.3223(8) angstrom,alpha = beta = 90 degrees,gamma = 120 degrees, and Z = 3. Its three-dimensional framework is composed of isolated GdO6 and SrO6 octahedra, RbOn(n = 6 and 8) polyhedra, and [B5O10](5-)clusters. Rb7SrGd2(B5O10)(3) exhibits multifunctional properties, and has both moderate second harmonic generation (SHG) responses (0.5 x KDP) and paramagnetic characteristics with mu(eff) = 8.18 mu(B). Thermal stability, Fourier transform infrared spectroscopy, and UV-Vis-NIR diffuse reflectance spectroscopy were performed to characterize the title compound. Its electronic band structures and density of states were also investigated via first-principles calculations.