文摘

Hydrothermal reactions of lanthanide oxide, lead chloride, I₂O₅, and H₂O at 200 °C led to four novel quaternary compounds, namely, Ln₃Pb₃(IO₃)₁₃(μ³−O) (Ln = La−Nd). They are isostructural, and their structures feature a complicated 3D network composed of LaO₉ and PbO₆ polyhedra interconnected by asymmetric IO₃ groups. Ln₃Pb₃(IO₃)₁₃(μ³−O) (Ln = La, Pr, Nd) display moderate second harmonic generation efficiencies of about 2.0, 1.0, and 0.8 times the value of KH₂PO₄, respectively. These compounds are thermally stable up to 520 °C. Luminescence measurements indicate that Ln₃Pb₃(IO₃)₁₃(μ³−O) (Ln = Ce, Pr, Nd) exhibit strong emission bands in the visible or near IR region. Magnetic studies indicate that there exist significant antiferromagnetic interactions between magnetic centers in Ln₃Pb₃(IO₃)₁₃(μ³−O) (Ln = Pr, Nd).