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Showing papers by "Jian Chen published in 1998"


Journal ArticleDOI
TL;DR: In this article, the temperature dependence of microwave surface resistance of YBa2Cu3O7-x (YBCO) thin films with different microstructures at 10 GHz, using a coplanar resonator technique, was investigated.
Abstract: This paper investigates the temperature dependence of microwave surface resistance (RS) of YBa2Cu3O7-x (YBCO) thin films with different microstructures at 10 GHz, using a coplanar resonator technique. YBCO thin films with different grain sizes were obtained as a result of changing the quenching procedure after film deposition by dc sputtering. The value of RS was found to vary with varying surface morphology and can be explained by the coupled grain model (CGM) when a temperature-dependent grain boundary resistance (R) is used. The temperature (T) dependence of R is given by R=R0+C(T/TC)2T, where TC is the superconducting critical temperature, and R0 and C are the fitting parameters, depending on the properties of each sample.

1 citations


Journal ArticleDOI
TL;DR: In this article, an enhanced AC Josephson effect for YBa2Cu3O7-δ grain boundary Josephson junctions driven by two rf sources has been demonstrated and the maximum heights of the first Shapiro step have been obtained and are in good agreement with simulations based on the resistively shunted junction (RSJ) model.
Abstract: Enhanced AC Josephson effect for YBa2Cu3O7-δ grain boundary Josephson junctions driven by two rf sources has been demonstrated Maximum heights of the first Shapiro step have been obtained and are in good agreement with simulations based on the resistively shunted junction (RSJ) model