TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The metal nitrate component (II) is applied in solution, specifically a solution in water and/or a 1-6C saturated alcohol; and is especially a compound (II'). In particular (II) is a mixture of at least two rare earth metal nitrates or a polynary rare earth metal nitrate containing at least two rare earth metals and (I) is a mixed rare earth metal oxide; or (II) is a mixture of at least two transition metal nitrates or a polynary transition metal nitrate containing at least two rare earth metals and (I) is a mixed transition metal oxide. Thermal decomposition of (II) is carried out at at least 500 (especially at least 700) degrees C, preferably by radiative heating (especially using a laser). Application and/or decomposition of (II) is optionally carried out under vacuum and/or inert gas. (A) is optionally pretreated by oxidation followed by reduction; or by heating to 1250 degrees C and cooling at 0.2 K per second or less under ultra-high vacuum. The process optionally includes converting the obtained metal oxide layer into a field effect transistor (FET). EXAMPLE - A pure silicon substrate was ultrasonically treated, washed with acetone, boiled in sulfuric acid-hydrogen peroxide (3:1) (to give a defined oxide layer) and immersed in 5% hydrofluoric acid at room temperature (to remove the oxide layer), treated with 40% ammonium fluoride solution (containing added 35% ammonium sulfite solution in ratio 15:1) under nitrogen and rinsed with distilled water for not more than 10 seconds. The pretreated substrate (having an oxide-free, hydrogen-terminated silicon surface) was placed in an ultra-high vacuum chamber, immersed in an isopropanolic solution of lanthanum nitrate, withdrawn, heated under ultra-high vacuum to 650 degrees C at 0.5 K per second, held at this temperature for 60 seconds and cooled to room temperature. Studies by spectroscopy and electron microscopy showed that the lanthanum nitrate was converted into lanthanum oxide and that the obtained ca. 10 nm thick lanthanum oxide layer on the substrate was homogeneous, flat and free of roughness and cavities. The oxide layer had a suitable dielectric value for production of integrated circuits, e.g. MOSFET's.