A method of forming an A site deficient thin film manganate material on a substrate from corresponding precursor(s), comprising liquid delivery and flash vaporization thereof to yield a precursor vapor, and transporting the precursor vapor to a chemical vapor deposition reactor for formation of an A site deficient manganate thin film on a substrate. The invention also contemplates a device comprising an A site deficient manganate thin film, wherein the manganate layer is formed on the substrate by such a process and is of the formula La_xM_yMnO₃, where M=Mg, Ca, Sr, or Ba, and (x+y)1.0, and preferably from about 0.5 to about 0.99.