title: Second-harmonic generating properties of polar noncentrosymmetric aluminoborate solid solutions, Al(5-x)Ga(x)BO9 (0.0 ≤ x ≤ 0.5).
abstract: A series of solid solutions of polar aluminoborate materials, Al(5-x)Ga(x)BO(9) (0.0 ≤x≤ 0.5) have been synthesized by standard solid-state reactions using Al(2)O(3), Ga(2)O(5), and B(OH)(3) as reagents. The phase purities, crystal structures, and solid solution behavior of the reported materials have been investigated by powder X-ray diffraction. Solid solutions of Al(5-x)Ga(x)BO(9) crystallize in the polar noncentrosymmetric space group, Cmc2(1), with a three-dimensional structure consisting of distorted MO(4), MO(5), MO(6), and BO(3) polyhedra (M = Al or Ga). Powder second-harmonic generating (SHG) measurements on the Al(5)BO(9) using 1064 nm radiation, indicate the material has a SHG efficiency of approximately 2 times that of α-SiO(2) and is not phase-matchable (type 1). Further nonlinear optical (NLO) measurements on the Al(5-x)Ga(x)BO(9) solid solutions indicate a sharp increase in SHG efficiency up to 10 times that of α-SiO(2) for x≥ 0.4. Close structural examination suggests that the alignment of the asymmetric π-delocalization of BO(3) groups is responsible for the abrupt increase of SHG efficiency.
authors.affiliation: Department of Chemistry, Chung-Ang University, Seoul, Republic of Korea.
authors.forename: Yiseul
authors.initials: Y
authors.lastname: Shin
authors.forename: Dong Woo
authors.initials: DW
authors.lastname: Lee
authors.forename: Jongin
authors.initials: J
authors.lastname: Hong
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Kwak
authors.forename: Kang Min
authors.initials: KM
authors.lastname: Ok