Comparative assessment of optical nonlinearity of members of the family of shortite-type double borates Na3Re2(BO3)3 (Re = La, Pr, Nd, Sm, Eu)

We obtained double borates of the composition Na3RE2(BO3)3 (RE = La, Pr, Nd, Sm, Eu) using ceramic technology. Na3Pr2(BO3)3 and Na3Eu2(BO3)3 have been synthesized for the first time. The unit cell parameters were refined using the Le Bail method, the obtained compounds crystallize in the space group Amm2 and are classified as shortite-type double borates. We have estimated he optical nonlinearity of the obtained double borates using the Kurtz-Perry powder method. The second harmonic generation intensity values in shortite-type borate powders relative to a-SiO2 range from 7 to 10 and increase with the lanthanide ionic radius.