Magnetic noise in YBCO thin films and its relationship to growth morphology

We report preliminary measurements of the magnetic noise from a series of thin YBCO films close to the superconducting transition. This is part of a more extended study of the relationship of flux noise to film thickness and morphology. We find that there are two contributions to the noise, one which is dominant at and above the noise peak and is a function of the temperature dependent resistivity of the film and another which contributes the conventional 1/f noise and is dominant at lower temperatures. The relative contributions are affected by both magnetic field and film morphology.