AC losses of YBCO strips on YSZ/hastelloy substrates

The effect of subdividing superconducting YBCO films on YSZ-buffered hastelloy substrates into arrays of parallel strips on the AC loss was investigated. Measurements of the loss component of the AC susceptibility, chi " revealed that the frequency-independent hysteretic contribution to chi ", which is dominant at low frequencies (f less than or similar to 1 kHz), decreased by a factor 1/N when the film was subdivided into N parallel strips. As the strips were made wider or the separation between them made smaller, the hysteretic chi " increased. The eddy current contribution to chi ", which originates from the metallic substrate, was found to become dominant with increasing frequency and approached a linear frequency dependence at high frequencies. The experimental findings are in close agreement with theoretical predictions of the AC loss in x-arrays of YBCO strips on metallic substrates.