Detailed measurements of the critical current density jc of YBa2Cu3O72 d films grown by pulsed laser deposition reveal the increase of jc as a function of film thickness. Both this thickness dependence and the field dependence of the critical current are consistently described using a generalization of the theory of strong pinning of Ovchinnikov and Ivlev @Phys. Rev. B 43, 8024 ~1991!#. From the model, we deduce values of the defect density (1021 m23) and the elementary pinning force, which are in good agreement with the generally accepted values for Y2O3 inclusions. In the absence of clear evidence that the critical current is determined by linear defects or modulations of the film thickness, our model provides an alternative explanation for the rather universal field dependence of the critical current density found in YBa2Cu3O72 d films deposited by different methods.
Strong pinning in high temperature superconducting films
Barbanera S
2002
Abstract
Detailed measurements of the critical current density jc of YBa2Cu3O72 d films grown by pulsed laser deposition reveal the increase of jc as a function of film thickness. Both this thickness dependence and the field dependence of the critical current are consistently described using a generalization of the theory of strong pinning of Ovchinnikov and Ivlev @Phys. Rev. B 43, 8024 ~1991!#. From the model, we deduce values of the defect density (1021 m23) and the elementary pinning force, which are in good agreement with the generally accepted values for Y2O3 inclusions. In the absence of clear evidence that the critical current is determined by linear defects or modulations of the film thickness, our model provides an alternative explanation for the rather universal field dependence of the critical current density found in YBa2Cu3O72 d films deposited by different methods.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
