Synthesis and characterization of optically nonlinear and light emitting lanthanide borates

Abstract

Lanthanide borates, LnBO 3 (Ln = La, Pr and Nd), were prepared via supercritical hydrothermal methods in sizes up to 3×0.5×0.5 mm and their crystallography and physical and optical properties studies. The materials are thermally stable up to at least 1000 °C and their crystal structure, although previously thought to be centric orthorhombic, is shown to be orthorhombic yet acentric as is confirmed by the observance of second harmonic generated light. Absorption and luminescence from the NdBO 3 and PrBO 3 is provided and discussed, as is the corroboration that these materials have bandgaps well above 5 eV. This works marks the lanthanide borates as candidate materials for deep-UV and nonlinear optical applications.