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Published on: February 9, 2017
Strong second harmonic generation from the tantalum thioarsenates A3Ta2AsS11 (A = K and Rb)
Tarun K Bera1, Joon I Jang, John B Ketterson
1Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
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).
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