A dielectric thin film material and method of preparation in which
precursors are provided to form barium strontium titanate with lanthanum
(La) added as a dopant. The precursors and La dopant are mixed with a
solvent forming a solution which is deposited on a substrate to form a
continuous film composition. In various embodiments, the dielectric thin
film has a composition of (1-y)Ba.sub.0.6 Sr.sub.0.4 TiO.sub.3 -(y)La,
where y=0 to 10-mol. The thin film material has dielectric and insulating
properties suitable for tunable microwave applications.
