Lithium niobate nanoparticles: Orientation in externally applied electric fields

The spontaneous polarization in lithium niobate leads to charged c-faces. It turns out that these surface charges of lithium niobate nanoparticles are not fully compensated. This leads to a remaining electrical dipole moment. We synthesize lithium niobate nanoparticles with a sol-gel method and measure their orientation in externally applied electric fields using this effect. By introducing dopants of different concentration and changing ambient conditions such as temperature, we investigate the various dependences of the dipole moment, which is generally about 10-3 of the dipole moment present for the uncompensated spontaneous polarization.