Epitaxial growth and properties of YBa2Cu3O7−y/LaSrGaO4/YBa2Cu3O7−y trilayer structures

Abstract

We report the successful synthesis of insulating LaSrGaO4(LSGO) thin films and YBa2Cu3O7−y(YBCO)/LSGO heteroepitaxial multilayer structures using a pulsed laser deposition technique. SrTiO3(STO)(100) was used as a substrate. The formation of highly c-axis oriented YBCO/LSGO/YBCO trilayer structures is demonstrated. Epitaxial YBCO films on LSGO//STO and LSGO/YBCO//STO have a zero resistance temperature of 88.5 and 88.3 K, respectively. Sandwich-type YBCO/LSGO/YBCO junctions were produced by a suitable patterning technique. The observed (dI/dV)-V characteristics exhibit a clear single gap structure (width ∼26 meV) at temperatures below 30 K.

High Quality (100) and (001) Oriented Substrates Prepared from Czochralski Grown SrLaGaO4and SrLaAlO4Single Crystals

“…SrLaΑlO4 and SrLaGaO4 are currently considered [2][3][4][5][6] as some of the best substrate materials for the epitaxy of high-Τc superconductors. Taking into account the small mismatch between the substrate and HTSC layers, the application areas include: -(001) oriented SrLaGaO4 for the deposition of YBaCuO [2,3], and 1212 and 1223 phases of Hg based superconductors [4] with c-axis perpendicular to the substrate surface, -(100) oriented SrLaGaO 4 for the deposition of YBaCuO [5], and 1212 mercury films with c-axis parallel to the substrate surface, -(001) oriented SrLaΑlO4 [6] for the deposition of La2-x Srx CuO4.…”

Growth of a multilayer garnet crystal double-clad waveguide structure by pulsed laser deposition

“…PLD has been used previously for multilayer deposition of superconducting films [27]; although these layers were thinner than the thicknesses desired for double-clad waveguide structures, this serves as an initial proof that layers of multi-component materials can be built up using PLD. The only remaining prerequisite therefore for our desired multilayer fabrication is to show that PLD is capable of sequential growth of several layers of alternating garnet crystal species of order microns in thickness without the quality of the layers suffering during progressive growth.…”

Temperature dependence of the FIR reflectance of LaSrGaO4

“…[11] A number of studies of junctions utilizing LaSrGaO 4 as a substrate or as a barrier layer have been published, pointing to its potential in device manufacturing. [12][13][14][15] One study of a variety of substrates suggests that LaSrGaO 4 may allow the manufacture of a microwave resonator and filter with a temperature independent center frequency. [16] A study of the infrared properties of the substrate material serves several goals.…”