Evaluation of LaSrGaO4 as a substrate for YBa2Cu3O7−δ

We present a comparison study between YBa2Cu3O7−δ thin films deposited on LaSrGaO4 substrates. The LaSrGaO4 crystals were grown, cut and polished in-house while the LaAlO3 substrates were prepared commercially. The deposited films were characterized by a variety of techniques including DC resistivity, critical current density, X-ray diffraction including rocking-curve analysis and scanning electron microscopy. Growth temperatures above 780°C on both substrates yielded highly oriented c-axis material with excellent transport properties. Because LaSrGaO4 has the advantage of being untwinned, a desirable property for microwave-device applications, we conclude that it has much promise as a potential substitute for LaAlO3.