Properties of inductance and magnetic penetration depth in (103)-orientedYBa2Cu3O7−δthin films

Abstract

We present a study of the anisotropy of the inductance in (103) ${\text{YBa}}_{2}{\text{Cu}}_{3}{\text{O}}_{7\ensuremath{-}\ensuremath{\delta}}$ (YBCO) films. YBCO superconducting quantum interference devices (SQUIDs) were fabricated by the biepitaxial technique. SQUIDs with (001)- and (103)-oriented YBCO electrodes characterized by different grain-boundary angles were realized on the same chip. Two extrainjection lines were attached to the (103) YBCO electrode. These devices, when operated in current injection mode, allow us to measure the inductance of the (103) YBCO electrode. We have found that the inductance $L$ of the (103) YBCO can differ by a factor of 20 in the two extreme cases: $L$ determined by current transport parallel to the $ab$ planes and $L$ dominated by the transport in the $c$-axis direction. The full in-plane angular dependence of the inductance has been obtained by considering geometrically identical SQUIDs oriented with different angles with respect to the [100] direction of the (103) film. From these measurements, we have determined the London penetration depths in the $ab$ direction ${\ensuremath{\lambda}}_{ab}$ and the $c$ direction ${\ensuremath{\lambda}}_{c}$ and their temperature dependence.