A. David

Anomalous exchange bias at collinear/noncollinear spin interface

We report on the interfacial magnetic coupling in manganite bilayers of collinear ferromagnetic La0.7Sr0.3MnO3 and noncollinear multiferroic TbMnO3. Exchange bias is observed at the Néel temperature of TbMnO3 (~41 K) due to the onset of long-range antiferromagnetic ordering in the Mn spin sublattice. Interestingly, an anomalous plateau of exchange bias emerges at the ordering temperature of Tb spins (~10 K), and we ascribe this unique feature to the strong coupling between Tb and Mn spin sublattices in TbMnO3, which in turn influences the magnetic coupling across the interface. On the other hand, the enhancement of coercivity in La0.7Sr0.3MnO3/TbMnO3 shows monotonous temperature dependence. Our results illustrate a strong interfacial magnetic interaction at the La0.7Sr0.3MnO3/TbMnO3 interface, highlighting the roles of competing spin orders, magnetic frustration, and coupling between multiple spin sublattices in artificial collinear/noncollinear spin heterostructures.

Incipient ferroelectricity in 2.3% tensile-strained CaMnO3 films

Epitaxial CaMnO3 films grown with 2.3% tensile strain on (001)-oriented LaAlO3 substrates are found to be incipiently ferroelectric below 25 K. Optical second harmonic generation (SHG) was used for the detection of the incipient polarization. The SHG analysis reveals that CaMnO3 crystallites with in-plane orientation of the orthorhombic b axis contribute to an electric polarization oriented along the orthorhombic a (respectively c) axis in agreement with the predictions from density functional calculations.

Surface properties of atomically flat poly-crystalline SrTiO3.

Comparison between single- and the poly-crystalline structures provides essential information on the role of long-range translational symmetry and grain boundaries. In particular, by comparing single- and poly-crystalline transition metal oxides (TMOs), one can study intriguing physical phenomena such as electronic and ionic conduction at the grain boundaries, phonon propagation, and various domain properties. In order to make an accurate comparison, however, both single- and poly-crystalline samples should have the same quality, e.g., stoichiometry, crystallinity, thickness, etc. Here, by studying the surface properties of atomically flat poly-crystalline SrTiO3 (STO), we propose an approach to simultaneously fabricate both single- and poly-crystalline epitaxial TMO thin films on STO substrates. In order to grow TMOs epitaxially with atomic precision, an atomically flat, single-terminated surface of the substrate is a prerequisite. We first examined (100), (110), and (111) oriented single-crystalline STO surfaces, which required different annealing conditions to achieve atomically flat surfaces, depending on the surface energy. A poly-crystalline STO surface was then prepared at the optimum condition for which all the domains with different crystallographic orientations could be successfully flattened. Based on our atomically flat poly-crystalline STO substrates, we envision expansion of the studies regarding the TMO domains and grain boundaries.

Room-temperature magnetism in LaVO 3 / SrVO 3 superlattices by geometrically confined doping

Based on the Hubbard model of strongly correlated systems, a reduction in the bandwidth of the electrons can yield a substantial change in the properties of the material. One method to modify the bandwidth is geometrically confined doping, i.e., the introduction of a (thin) dopant layer in a material. In this Rapid Communication, the magnetic properties of

Constrained ferroelectric domain orientation in (BiFeO3)m(SrTiO3)n superlattice

{\text{LaVO}}_{3}/{\text{SrVO}}_{3}

Effects of electrode material and configuration on the characteristics of planar resistive switching devices

superlattices, in which the geometrically confined doping is produced by a one monolayer thick

Domain-related origin of magnetic relaxation in compressively strained manganite thin films

{\text{SrVO}}_{3}

Microstructure of epitaxial strained BiCrO3 thin films

film, are presented. In contrast to the solid solution

Influence of Oxygen Pressure and Aging on LaAlO3 Films Grown by Pulsed Laser Deposition on SrTiO3 Substrates

{\text{La}}_{1\ensuremath{-}x}{\text{Sr}}_{x}{\text{VO}}_{3}

BiFeO3/La0.7Sr0.3MnO3 heterostructures deposited on spark plasma sintered LaAlO3 substrates

, such superlattices have a finite magnetization up to room temperature. Furthermore, the total magnetization of the superlattice depends on the thickness of the