Electro-optic Properties Of Epitaxial Sr_(0.6)ba_(0.4)nb_2o_6 Films Grown On Mgo Substrates Using Li_xni_(2-x)o Buffer Layer

摘要

Textured Li_xNi_(2-x)O (LNO) thin films have been fabricated on (001)MgO substrates by pulsed laser deposition technique. The as-deposited LNO films shows a conductivity of 2.5 × 10~3 Ωm and possess a transmittance of about 35% in the visible region. Subsequent deposition of Sr_(0.6)Ba_(0.4)Nb_2O_6 (SBN60) thin film on these LNO-coated MgO substrates resulted in a textured SBN layer with a <001> orientation perpendicular to the substrate plane. Phi scans on the (221) plane of the SBN layer indicated that the films have two in-plane orientations with respect to the substrate. The SBN unit cells were rotated in the plane of the film by ±8.2° as well as ±45° with respect to the LNO/MgO substrate. Besides the highly (00l)-orientation, the SBN films also exhibited a dense mi-crostructure as shown by scanning electron microscopy. The electro-optic coefficient (r_(33)) of the SBN film was measured to be 186 pm/V. On the basis of our results, we have demonstrated that the LNO film can be used as a buffer layer as well as a transparent bottom electrode for waveguide applications. The SBN/LNO heterostructure is also a suitable candidate for integrated electro-optics devices.