Magnetic properties of heteroepitaxial La0.7Sr0.3MnO3/SrTiO3 superlattices

We have investigated the magnetic properties of La0.7Sr0.3MnO3(LSMO)/SrTiO3(STO) superlattices on a number of samples with the thickness d(LSMO) greater than or equal to d(STO) in order to understand the interface magnetism and the possible interlayer magnetic coupling. A series of multilayers with several thickness combinations of d(LSMO) and d(STO), varying from 1.9 to 10 nm was fabricated on SrTiO3(100) substrates by pulsed laser deposition. A ferromagnetic transition was observed for all studied films and the transition temperature decreased with d(LSMO), without showing a clear dependence on d(STO). The spontaneous magnetization was found to decrease with d(LSMO) though the decrease is not as strong as expected for a magnetically disordered surface of the LSMO layers. (C) 2001 American Institute of Physics.