title: Strong second harmonic generation from the tantalum thioarsenates A3Ta2AsS11 (A = K and Rb).
abstract: The strongly anisotropic thioarsenates A(3)Ta(2)AsS(11) are stabilized in a polysulfide flux. All compounds contain the same parallel (1)/(infinity)[Ta(2)AsS(11)(3-)] polymeric anionic chains, but the size of the alkali-metals has a profound effect on the packing of the chains. The K(+) or Rb(+) favor noncentrosymmetric packing of the chains, whereas the larger Cs(+) favors the centrosymmetric packing. The chains feature the combination of two asymmetric units [Ta(2)S(11)] and [AsS(3)] and exhibit strong nonlinear optical (NLO) second harmonic generation (SHG) response. Polycrystalline samples exhibit is up to approximately 15 times stronger SHG than that of commercially used AgGaSe(2).
authors.affiliation: Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Tarun K
authors.initials: TK
authors.lastname: Bera
authors.forename: Joon I
authors.initials: JI
authors.lastname: Jang
authors.forename: John B
authors.initials: JB
authors.lastname: Ketterson
authors.forename: Mercouri G
authors.initials: MG
authors.lastname: Kanatzidis