title: Measuring the three-dimensional structure of ultrathin insulating films at the atomic scale.
abstract: The increasing technological importance of thin insulating layers calls for a thorough understanding of their structure. Here we apply scanning probe methods to investigate the structure of ultrathin magnesium oxide (MgO) which is the insulating material of choice in spintronic applications. A combination of force and current measurements gives high spatial resolution maps of the local three-dimensional insulator structure. When force measurements are not available, a lower spatial resolution can be obtained from tunneling images at different voltages. These broadly applicable techniques reveal a previously unknown complexity in the structure of MgO on Ag(001), such as steps in the insulator-metal interface.
authors.affiliation: IBM Almaden Research Center , 650 Harry Road, San Jose, California 95120, United States.
authors.forename: Susanne
authors.initials: S
authors.lastname: Baumann
authors.forename: Ileana G
authors.initials: IG
authors.lastname: Rau
authors.forename: Sebastian
authors.initials: S
authors.lastname: Loth
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Lutz
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Heinrich