Substrate surfaces terminated with a specific surface reconstruction are a prerequisite for the controlled epitaxial growth of most materials. Focusing on SrTiO3 (001) substrates, it has recently been shown that in situ substrate termination by thermal annealing has decisive advantages over standard termination methods. We report here that in situ substrate termination is a generally applicable method not restricted to SrTiO3 crystals. We specifically demonstrate the successful surface preparation of doped SrTiO3 (001), LaAlO3 (001), NdGaO3 (001), DyScO3 (110), TbScO3 (110), MgO (001), and Al2O3 (0001) surfaces.

The tetragonal domain structure in SrTiO 3 (STO) is known to modulate the normal-state carrier density in LaAlO 3 /SrTiO 3 (LAO/STO) heterostructures, among other electronic properties, but the effect of STO domains on the superconductivity in LAO/STO has not been fully explored. Using a scanning SQUID susceptometer microscope to map the superconducting response as a function of temperature in LAO/STO, we find that the superconducting transition temperature is spatially inhomogeneous and modulated in a pattern that is characteristic of structural domains in the STO.

We report on extensive investigations of magnetism at the n-type LaAlO 3 /SrTiO 3 interface performed by utilizing a spectrum of local and integrative analytical techniques: Scanning superconducting quantum interference device microscopy, polar Kerr magnetometry, ferromagnetic resonance, and magnetic torque magnetometry. The samples originated from the same wafers. For nominally fully oxidized samples, we find that the mere presence of the conducting interface does not induce magnetism to values exceeding already present magnetic signals originating from the substrates, irrespective of the measurement technique. With the controlled introduction of oxygen vacancies, however, the different analytical techniques with their inherently different sensitivities and potential interactions with possible magnetic moments in the samples yield different results concerning the existence of magnetism. These unexpected differences obtained with the various measurement techniques are a possible source of the disagreement in the literature about the existence of ferromagnetism at LaAlO 3 /SrTiO 3 interfaces.