Synthesis of Highly Oriented K(Ta,Nb)O 3 (Ta:Nb = 65:35) Film Using Metal Alkoxides

Highly oriented K(Ta,Nb)O 3 (Ta:Nb = 65:35) (KTN) thin films of perovskite structure were synthesized successfully on Pt(100)/MgO(100) substrates from a metal alkoxide solution through reaction control. Homogeneous KTN coating solutions prepared from KOC 2 H 5 , Ta(OC 2 H 5 ) 5 , and Nb(OC 2 H 5 ) 5 in ethanol were analyzed by 1 H, 13 C, and 93 Nb NMR spectroscopy. The KTN precursor included a molecular‐level mixture of K[M(OC 2 H 5 ) 6 ] (M = Ta, Nb) units interacting in ethanol solution. X‐ray pole figure measurement showed that perovskite KTN films crystallized on Pt(100)/MgO(100) substrates had not only a (100) orientation but also a three‐dimensional regularity of grains. The remanent polarization and coercive field of the KTN film (thickness, 1.0 μm) crystallized at 700°C were 1.5 μC/cm 2 and 8.7 kV/cm, respectively, at 225 K.