Abstract
Perfect c-axis oriented Na0.5K0.5NbO3 (NKN) films have been pulsed laser deposited on Al2O3(0112) single crystals (r-cut sapphire) for voltage tunable microwave device applications. Thickness dependence of dielectric performance of the NKN/sapphire interdigital capacitors (IDCs) has been studied. 40 V bias tunability and dielectric loss tan δ of 4 μm slot IDCs have been found to be 24.6 % and 2.86 % for 1.2 μm thick NKN film, and 6.1 % and 0.83 % for 0.14 μm thick NKN film, respectively. Low leakage currents and high breakdown voltages are observed in these structures.