During the last quarter, new procedures were developed and implemented to improve reliability and repeatability of release characteristics from the temporary substrate (i.e., silicon wafer) and to minimize through-thickness defects in a 6-inch diameter film, 3 microns in thickness. With the new procedures, we have been able to consistently produce essentially stress free films, with zero or minimal defects (less than 5) across a 6-inch diameter area. (It is important to note that for those films containing pinholes, a procedure has been developed to repair the pinholes to form a gas tight seal). The films are all within the identified tolerance range for composition (i.e., 60 {+-} 0.2 % Pd). A number of these films have subsequently been shipped to IdaTech for evaluation and integration into their test module. Colorado School of Mines continued their high temperature evaluation of 6 micron thick, sputtered Pd-Cu films. Pure hydrogen permeability increased up to 400 C while the membrane was in the {beta}-phase and dropped once the temperature increased to over 450 C. Above this temperature, as confirmed by the binary phase diagram, the film transforms into either a mixed {alpha}/{beta} or pure {alpha} phase. The same trend was observed for a baseline …

Efforts in this quarter were concentrated on developing vacuum processing procedures to produce thinner (<4 {micro}m-thick), defect-free films over larger areas (>100 cm{sup 2}). We continued to test three different types of rigid supporting substrates, thermally oxidized silicon (10 cm diameter), polished borosilicate glass (10 cm diameter), and soda-lime glass (>100 cm{sup 2} areas), each representing a different cost, surface roughness, and chemistry. Mechanical integrity, defect density, and release characteristics of the films, though similar for the oxidized silicon and borosilicate glass, were distinctly different for the inexpensive soda-lime (float) glass; i.e., more sensitive to surface impurities. In general, films less than 4 {micro}m-thick were shown to be very sensitive to surface condition of the supporting substrate, particularly in the case of the soda-lime glass, to the point where surface strain overrode and dominated the intrinsic bulk stresses that are produced during the growth process. Therefore, in the near term (over the next quarter), large area films (>100 cm{sup 2}) will be produced at a minimum thickness of 5 {micro}m while further development will be conducted in subsequent quarters to reduce membrane thickness in large area films. Continued hydrogen permeation experiments and characterization of 5 and 10 {micro}m-thick, Pd-Cu films, …