Abstract
Two novel noncentrosymmetric borates oxides, MBi 2B 2O 7 or MBi 2O(BO 3) 2 ( M Ca, Sr), have been synthesized by solid-state reactions in air at temperatures in the 600–700 °C range. Their crystal structures have been determined ab initio and refined using powder neutron diffraction data. CaBi 2B 2O 7 crystallizes in the orthorhombic Pna2 1 space group with a=8.9371(5) Å, b=5.4771(3) Å, c=12.5912(7) Å, Z=4, R wp=0.118, χ 2=2.30. SrBi 2B 2O 7 crystallizes in the hexagonal P6 3 space group with a=9.1404(4) Å, c=13.0808(6) Å, Z=6, R wp=0.115, χ 2=4.15. Large displacement parameters suggest the presence of disorder in SrBi 2B 2O 7 as also revealed by diffuse 2× a superstructure reflections in electron diffraction patterns. Both structures are built of identical (001) neutral layers of corner-sharing BO 3 triangles and MO 6 trigonal prisms forming six-membered rings in which Bi 2O groups are located. Adjacent layers are stacked in a staggered configuration and connected through weak Bi–O bonds. A moderate efficiency for second harmonic generation (SHG) has been measured for a powder sample of CaBi 2B 2O 7 ( d eff=2 d eff(KDP)).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
