SYNTHESIS OF BA2NANB5O15 POWDERS AND THIN-FILMS USING METAL ALKOXIDES

Transparent and highly oriented Ba2NaNb5O15 (BNN) thin films have been prepared by using metal alkoxides. A homogeneous precursor solution w as prepared by the controlled reaction of NaOC2H5, Nb(OC2H5)(5), and b arium metal. The BNN precursor included a molecular-level mixture of N aNb(OC2H5)(6) and Ba[Nb(OC2H5)(6)](2) in ethanol. The alkoxy-derived p owder crystallized to a low-temperature phase, and then transformed to orthorhombic BNN (tungsten bronze) at 600 degrees C BNN precursor fil ms on substrates crystallized to orthorhombic BNN at 800 degrees C via the low-temperature phase. Highly (002) oriented BNN films of tungste n bronze structure were successfully prepared on MgO (100) substrates at 700 degrees C by using BNN underlayer.