Effect of Stacking Layers on the Microwave Dielectric Properties of MgTiO ₃ /CaTiO ₃ Multilayered Thin Films

Abstract

Effect of stacking layers on the microwave dielectric properties of the MgTiO 3 /CaTiO 3 (MTO/CTO) multilayered thin films prepared by the metalorganic solution deposition technique (MOSD) was investigated. As the thickness of CTO film in the MTO/CTO multilayered films increased, the dielectric constant ( K ) increased and temperature coefficient of dielectric constant ( TCK ) changed from positive to negative values by dielectric series mixing rule. Especially, MTO(100 nm)/CTO(200 nm) multilayered films exhibited a TCK of +10 ppm/°C, indicating temperature stability. The dielectric losses (tan δ) of MTO/CTO multilayered films increased with an increase of CTO layers. This result was attributed to the fact that the stresses induced by the higher thermal‐expansion coefficient of CTO than that of MTO. Also, as compared with MTO(100 nm)/CTO(200 nm) film, the K and TCK of MTO(50 nm)/CTO(200 nm)/MTO(50 nm) film were not changed, but the dielectric losses increased. This result indicated that the dielectric loss was affected by the number of interfaces between CTO and MTO layers.