Electronic noise in Ba/sub 2/YCu/sub 3/O/sub 7/ films at high temperatures: a possible connection to stress relaxation

Two types of electronic noise have been observed in Ba/sub 2/YCu/sub 3/O/sub 7/ at high temperature. One type is probably due to temperature and pressure fluctuations in the environment of the sample. Because of the known sensitivity of Ba/sub 2/YCu/sub 3/O/sub 7/ resistance to both temperature and pressure, this mechanism translates into 10 to 100 nV per root Hz of noise at temperatures above 750 K. The second type is more intrinsic, and may be related to stress relaxation in the film induced by the structural changes associated with the orthorhombic-tetragonal transition near 950 K.<
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