title: Giant Controllable Magnetization Changes Induced by Structural Phase Transitions in a Metamagnetic Artificial Multiferroic.
abstract: The realization of a controllable metamagnetic transition from AFM to FM ordering would open the door to a plethora of new spintronics based devices that, rather than reorienting spins in a ferromagnet, harness direct control of a materials intrinsic magnetic ordering. In this study FeRh films with drastically reduced transition temperatures and a large magneto-thermal hysteresis were produced for magnetocaloric and spintronics applications. Remarkably, giant controllable magnetization changes (measured to be as high has ~25%) are realized by manipulating the strain transfer from the external lattice when subjected to two structural phase transitions of BaTiO3 (001) single crystal substrate. These magnetization changes are the largest seen to date to be controllably induced in the FeRh system. Using polarized neutron reflectometry we reveal how just a slight in plane surface strain change at ~290C results in a massive magnetic transformation in the bottom half of the film clearly demonstrating a strong lattice-spin coupling in FeRh. By means of these substrate induced strain changes we show a way to reproducibly explore the effects of temperature and strain on the relative stabilities of the FM and AFM phases in multi-domain metamagnetic systems. This study also demonstrates for the first time the depth dependent nature of a controllable magnetic order using strain in an artificial multiferroic heterostructure.
authors.affiliation: Quantum Condensed Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Bennett
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.|Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996.
authors.forename: A T
authors.initials: AT
authors.lastname: Wong
authors.affiliation: Quantum Condensed Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.|Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Glavic
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
authors.forename: A
authors.initials: A
authors.lastname: Herklotz
authors.affiliation: Department of Physics, The University of California, San Diego, San Diego, CA 92110, USA.
authors.forename: C
authors.initials: C
authors.lastname: Urban
authors.affiliation: Department of Physics, The University of California, San Diego, San Diego, CA 92110, USA.
authors.forename: I
authors.initials: I
authors.lastname: Valmianski
authors.affiliation: Center for Nanoscale Materials Science, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Biegalski
authors.affiliation: Center for Nanoscale Materials Science, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
authors.forename: H M
authors.initials: HM
authors.lastname: Christen
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
authors.forename: T Z
authors.initials: TZ
authors.lastname: Ward
authors.affiliation: Quantum Condensed Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
authors.forename: V
authors.initials: V
authors.lastname: Lauter