11 research outputs found
d0 Ferromagnetic Interface Between Non-magnetic Perovskites
We use computational and experimental methods to study d0 ferromagnetism at a
charge- imbalanced interface between two perovskites. In SrTiO3/KTaO3
superlattice calculations, the charge imbalance introduces holes in the SrTiO3
layer, inducing a d0 ferromagnetic half-metallic 2D electron gas at the
interface oxygen 2p orbitals. The charge imbalance overrides doping by
vacancies at realistic concentrations. Varying the constituent materials shows
ferromagnetism to be a gen- eral property of hole-type d0 perovskite
interfaces. Atomically sharp epitaxial d0 SrTiO3/KTaO3, SrTiO3 /KNbO3 and
SrTiO3 /NaNbO3 interfaces are found to exhibit ferromagnetic hysteresis at room
temperature. We suggest the behavior is due to high density of states and
exchange coupling at the oxygen t1g band in comparison with the more studied d
band t2g symmetry electron gas.Comment: 5 pages, 5 figure
Orientation gradients in rapidly solidified pure aluminum thin films: comparison of experiments and phase-field crystal simulations
Rapid solidification experiments on thin film aluminum samples reveal the
presence of lattice orientation gradients within crystallizing grains. To study
this phenomenon, a single-component phase-field crystal (PFC) model that
captures the properties of solid, liquid, and vapor phases is proposed to model
pure aluminium quantitatively. A coarse-grained amplitude representation of
this model is used to simulate solidification in samples approaching micrometer
scales. The simulations reproduce the experimentally observed orientation
gradients within crystallizing grains when grown at experimentally relevant
rapid quenches. We propose a causal connection between formation of defects and
orientation gradients