Epitaxial MgB2 thin films on ZrB2 buffer layers: structural characterization by synchrotron radiation

Abstract

Structural and superconducting properties of magnesium diboride thin films grown by pulsedlaser deposition on zirconium diboride buffer layers were studied. We demonstrate that theZrB2 layer is compatiblewith the MgB2 two step deposition process. Synchrotron radiation measurements, inparticular anomalous diffraction measurements, allowed us to separateMgB2 peaksfrom ZrB2 ones and revealed that both layers have a single in plane orientation with a sharp interfacebetween them. Moreover, the buffer layer avoids oxygen contamination from the sapphiresubstrate. The critical temperature of this film is near 37.6 K and the upper critical fieldmeasured at the Grenoble High Magnetic Field Laboratory up to 20.3 T is comparable withthe highest ones reported in literature.