Exploration of artificial multiferroic thin-film heterostructures using composition spreads

The fabrication of a series of composition spreads consisting of ferroelectric BaTiO 3 and piezoelectric CoFe 2O 4 layers of varying thickness modulated at nanometer level in order to explore artificial magnetoresistance thin-film heterostructures was discussed. The scanning microwave microscopy and scanning superconducting quantum interference device microscopy were used for mapping the dielectric and magnetic properties as a function of continuously changing average composition across the spreads, respectively. The compositions in the middle of the spreads were found to exhibit ferromagnetism where as displaying a dielectric constant as high as ≈ 120.