Very high commutation quality factor and dielectric tunability in nanocomposite SrTiO(3) thin films with T(c) enhanced to >300 °C

We report on nanoengineered SrTiO(3)–Sm(2)O(3) nanocomposite thin films with the highest reported values of commutation quality factor (CQF or K-factor) of >2800 in SrTiO(3) at room temperature. The films also had a large tunability of dielectric constant (49%), low tangent loss (tan δ = 0.01) and a Curie temperature for SrTiO(3) > 300 °C, making them very attractive for tunable RF applications. The enhanced properties originate from the unique nanostructure in the films, with <20 nm diameter strain-controlling Sm(2)O(3) nanocolumns embedded in a SrTiO(3) matrix. Very large out-of-plane strains (up to 2.6%) and high tetragonality (c/a) (up to 1.013) were induced in the SrTiO(3). The K-factor was further enhanced by adding 1 at% Sc(3+) (acceptor) dopant in SrTiO(3) to a value of 3300 with the tangent loss being ≤0.01 up to 1000 kV cm(–1).