Effect of Thickness on the Structure and Dielectric Properties of CMN/CT Thin Films

Precursor solutions for Ca(Mg1/3Nb2/3)O3(CMN)and CaTiO3(CT)synthesis were obtained by Pechini method.CMN/CT dielectric heterogeneous thin films were prepared by spin-coating with CMN and CT precursor solutions in different stacking sequence.Effects of thickness,stacking sequence and thermal treatment on the structure and dielectric properties of CMN/CT thin films were investigated.The results indicated that pure perovskite phase was obtained in the CMN/CT dielectric heterogeneous thin films.And the dielectric enhancement phenomenon was presented,which due to the heterogeneous interfaces between CMN layer and CT layer.As the film thickness increased,the interface between heterogenerous layers became less distinct,and the grain size,surface roughness and dielectric loss all increased,and dielectric properties enhanced.The arrangement pattern had important effect on dielectric properties of heterogeneous thin films.The heterogeneous thin film with CT layer locating at bottom near the substrate had larger surface roughness than those with CMN layer locating at bottom.And the more heterogeneous interfaces existing in the heterogeneous thin films,the stronger effect of dielectric enhancement it will have.