Lithium niobate nanowires: Growth, second-harmonic and dielectrophoretic properties

This paper presents the growth, optical characterization, and dielectrophoretic response of lithium niobate (LiNbO₃) nanowires. These nanosize wires demonstrate similar optical characteristics as their bulk counterparts and may be utilized as second-harmonic radiating imaging probes (SHRIMPs), or manipulated using electric fields to orient them in a preferable direction. LiNbO₃ nanowires are prepared by a hydrothermal route, which enables simple, gram-scale production, similar to the synthesis of KNbO₃ nanowires. Second harmonic generation polarization response of a single nanowire is measured. Due to positive dielectrophoretic forces, the nanowires are aligned with the field. Increasing the conductivity of the suspension as well as the frequency of the applied electric field can change the type of dielectrophoretic force on the nanowire which will result in the nanowire to not be aligned with the field.