Patent attributes
The low Ta impurity content in pyrochlore ore makes it unnecessary to use a solvent extraction process to separate Nb from Ta. Consequently, niobium pentoxide powders using this ore can be produced at lower cost than competing mining/refining approaches, but in turn contain significant amounts of Ta impurities. SAW wafers are grown from melts produced by reacting niobium pentoxide powders containing Ta impurities at levels of 200 ppm or more by weight. Given proper amounts of starting powders, crystals can be grown with good yields and reproducible properties that satisfy typical SAW wafer specifications. The consistency across various lots of powders may be further improved by adding an appropriate amount of Ta pentoxide to the starting powders.
