Structures and Dielectric Properties of Cerium and Yttrium Alternately Doped Ba0.6Sr0.4TiO3 Films

摘要

Novel YBST/CeBST/YBST/CeBST and CeBST/YBST/CeBST/YBST films where BST, Y and Ce orderly represent barium strontium titanate and yttrium and cerium doped elements were designed and prepared, and their structures and dielectric properties were studied. The dielectric properties of the alternately doped films are more significantly improved than those of Ce or Y doped film because the alternate doping can make crystallization stronger, growing behavior better and doped mechanism from donor doping to acceptor doping. Also, the alternate doping order affects the dielectric properties by affecting the phase structures analyzed by X-ray diffraction (XRD) and morphologies observed by atomic force microscope (AFM). Ce and Y alternate doping may exert the advantages of increasing tunability for Ce doping and decreasing dielectric loss for Y doping, and hence is effective to achieve excellent dielectric properties for tunable microwave applications. In addition, the improved mechanisms are discussed.