The In-Plane Dielectric and Microwave Properties of Barium Stannate Titanate Thin Films

The microstructure and in-plane dielectric and microwave properties of barium stannate titanate Ba(Sn 0.15 Ti 0.85 )O 3 (BTS) thin films grown on c-plane Al 2 O 3 substrates through sol-gel process are investigated. X-ray diffraction and field emission scanning electron microscopy are used to characterize phase structure and microstructure of the thin films, respectively. Using interdigital capacitors (IDC) with Au electrodes on thin films, the dielectric constant and loss tangent as a function of applied voltage (0–40 V) are measured at low frequencies up to 1 MHz. Microwave properties of the films are measured at 10 GHz. This work clearly reveals the highly promising potential of BTS films for application in tunable microwave devices.