Construction of ferroelectric and/or ferromagnetic superlattices by laser MBE and their physical properties

We have constructed ferroelectric and/or ferromagnetic superlattices by a layer-by-layer successive deposition technique with a laser MBE. An ideal hetero-epitaxy can be obtained due to the similar crystal structure of the perovskite type ferroelectric BaTiO3, SrTiO3, Bi-based layered compounds and ferro- or antiferromagnetic LaFeO3, LaCrO3, (La,Sr)MnO3. In both superlattices, strain effect plays an important role for deterring their physical properties. In the Bi-based layer structured superlattices, we have controlled dielectric constant and ferroelectric properties. We also control the spin order on LaFeO3/LaCrO3 superlattices formed on SrTiO3(111) and (100) substrate. Such a spin structure(ferromagnetic order) cannot be realized in bulk samples.