No abstract

A new class of heterometallic heteroleptic alkoxides, M II 2 Ta 2 (acac) 2 (OEt) 12 , M II LCo, Ni, has been used as single-source precursors in order to obtain nanophase powders and films. M II 2 Ta 2 (acac) 2 (OEt) 12 was prepared via interaction of M II (acac) 2 , M II LCo, Ni, with Ta(OEt) 5 , in toluene and characterized structurally by single-crystal X-ray diffraction, IR and NMR spectroscopy. Oxide films were deposited by spin coating on Si-and SiO 2 -substrates. Multiple layers, with intermittent heat treatment, were applied to increase the thickness. After annealing at different temperatures and time, the films were characterized by powder X-ray diffraction and SEM. The films were homogeneous and the thickness could be varied between 0.14 mm and 0.67 mm, depending on solution concentration (0.20-0.28 M) and number of layers (3-6). The nanophase powders were also studied at different annealing temperatures. Powder X-ray diffraction of the films coated on Si-substrate and the nanophase powders revealed the presence of CoTa 2 O 6 and Co 3 O 4 phases for the cobalt-tantalum precursor. NiTa 2 O 6 and NiO phases were detected by powder X-ray diffraction with the nickel-tantalum precursor. Atomic force microscopy revealed the oxide films on the Si-substrate to be very smooth and the root mean square roughness was 2.4 nm for a three-layer oxide film with a thickness of 0.50 mm.