Dielectric properties of Ti-doped K(Ta,Nb)O3 thin films grown by pulsed laser deposition

We have investigated the growth and dielectric properties of K(Ta,Nb)O3 films doped with Ti. Titanium (+4) substitution on the group V (Nb/Ta) site should introduce an acceptor state, thus reducing dielectric losses due to defect-induced donor states. Using 3% Ti-doped targets, K(Ta,Nb)O3:Ti films were grown on MgO(0 0 1) crystals using pulsed-laser deposition. A reduction in the loss tangent was observed for Ti-doped K(Ta,Nb)O3 relative to undoped films, although a reduction in tunability is also seen. The crystallinity, morphology, dielectric constant, and tunability of K(Ta,Nb)O3:Ti films are reported.