Enhanced dielectric properties of Ca(Mg1/3Nb2/3)O3 / CaTiO3 multilayer heterogeneous thin films

Ca(Mg_1/3Nb_2/3)O₃/CaTiO₃ (CMN/CT) heterostructure dielectric thin films, with the same thickness but different arrangement patterns, were prepared by Pechini method. The effects of the heterogeneous interface on the structure and properties have been studied. The results showed that, in non-alternating arrangement films, single perovskite phase can only be obtained in TM heterostructure film, in which CaTiO₃ layer has grown on the substrate firstly, and the dielectric properties of this film is epsiv_r=47.5, tandelta=0.020 at 1MHz. Comparing with non-alternating arrangement film, all alternating arrangement films have single perovskite phase, and the existing of heterogeneous interface enhanced the dielectric properties of TMM and MMT alternating arrangement films by introducing space charges. And the dismatch between CMN and CT layers can avoid the harmful particle forming, improve crystallization and surface morphology, and keep the dielectric loss at a low level. At 1MHz, the dielectric constant (epsiv_r) of TMM and MMT films are 66.3 and 63.6, while both dielectric loss (tandelta) are 0.021.