TaTiOx layers prepared by magnetron sputtering from separate metal targets

Mixed oxide films of titanium and tantalum have been prepared by DC-reactive magnetron sputtering from separate targets in an Ar–O2 atmosphere. The oxygen partial pressure during magnetron operation is chosen such that no significant poisoning of the metal targets occurs. Composition of the mixed layers is determined by X-ray fluorescence and shows good reproducibility. Layers deposited are amorphous but crystallize in the Ta2O5 structure after heating to 1000 °C. The optical constants in the visible are determined from the transmittance of single layers. As an application interference stacks with up to 38 layers of TaTiOx/SiO2 and Ta2O5/SiO2 are prepared on compact tungsten–halogen lamps.