Fig xA a Custom NbCl cell with b tip
It has been demonstrated that a liquid heated bulk, filament heated tip, two zone effusion cell with an aperture plate is effective for the stable and controllable Gefitinib of metal-halide sources in an MBE environment. Using this source, high quality Nb thin films on sapphire have been grown. It has also been shown that the salt LiClO4 can be used as a solid/liquid state oxygen source evaporated from a standard effusion cell. Through an in situ Auger experiment, LiClO4 is shown to be a stronger oxidizer than molecular oxygen providing a pathway to potentially higher growth rates, likely due to the presence of both molecular and atomic oxygen evolving from the molten salt. Using the LiClO4 cell niobium oxides have been grown in Nb oxidation states +2, +3, and +5, including the multi-functional sub-oxide LiNbO2. It is also shown that pressure instabilities from the LiClO4 must be addressed to improve the quality of films grown by this method.
AcknowledgementsThis work was supported by the Defense Threat Reduction Agency, Basic Research Award # HDTRA-1-12-1-0031 administered by Dr. James Reed and Dr. Jacob Calkins, and by Dr. Abdel-Rahman A. El-Emawy at Vesco-NM.