Eur. Phys. J. AP 5, 3-8 (1999)
https://doi.org/10.1051/epjap:1999100

Suppression of the “notch effect” in microwave surface resistance in YBa₂Cu₃O₇ films on MgO (100) substrate by deposition of ultra-thin SrTiO₃ seed layers

¹ Unité Mixte de Physique CNRS / Thomson-CSF, 91404 Orsay, France
² LCR / Thomson-CSF, 91404 Orsay, France

Received: 28 May 1998
Revised: 30 September 1998
Accepted: 1 October 1998
Published online: 15 January 1999

Abstract

RHEED controlled ultra-thin buffer layers of SrTiO₃ have been deposited on (100) MgO by pulsed laser deposition to growth YBaCuO films for microwave applications. A buffer layer with a thickness between 2 and 15 nm, i.e. 5 to 40 unit cells of SrTiO₃, is sufficient to expand to more than 60 °C the range of deposition temperatures leading to low microwave surface resistance. The Rs values are as good as those obtained on LaAlO₃ substrates with a slighly lower magnetic field dependency. The SrTiO₃ seed layer induces an oriented epitaxial growth with YBCO [100] // MgO [100] over this range of deposition temperatures.