Interface ferromagnetism and orbital reconstruction in BiFeO3- La0.7Sr0.3MnO3 heterostructures

We report the formation of a novel ferromagnetic state in the antiferromagnet BiFeO3 at the interface with La0.7Sr0.3MnO3. Using x-ray magnetic circular dichroism at Mn and Fe L2,3-edges, we discovered that the development of this ferromagnetic spin structure is strongly associated with the onset of a significant exchange bias. Our results demonstrate that the magnetic state is directly related with an electronic orbital reconstruction at the interface, which is supported by the linearly polarized x-ray absorption measurement at oxygen K-edge.Comment: 17 pages, 4 figures, PRL in pres

Optical properties of self organized silver nanocolumns

9th International Conference on Laser Ablation, Tenerife, Spain, September 24-28, 2007N

Stabilisation of the cubic phase of HfO2 by Y addition in films grown by metal organic chemical vapor deposition

International audienc

Asynchronous current induced switching of rare earth and transition metal sublattices in ferrimagnetic alloys

Ferrimagnetic alloys are model systems for understanding the ultrafast magnetization switching in materials with antiferromagnetically-coupled sublattices. Here we investigate the dynamics of the rare-earth and transition-metal sublattices in ferrimagnetic GdFeCo and TbCo dots excited by spin-orbit torques with combined temporal, spatial, and elemental resolution. We observe distinct switching regimes in which the magnetizations of the two sublattices either remain syn-6 chronized throughout the reversal process or switch following different trajectories in time and space. In the latter case, we observe a transient ferromagnetic state that lasts up to 2 ns. The asynchronous switching of the two magnetizations is ascribed to the master-agent dynamics induced by the spin-orbit torques in combination with the weak antiferromagnetic coupling, which depends sensitively on the microstructure of ferrimagnets. A larger antiferromagnetic exchange between the two sublattices leads to faster switching and shorter recovery of the magnetization after a current pulse.We thank M. Baumgartner and C. Murer for fruitful discussions and help with the STXM measurements, and F. Binda for the assistance with the measurements at the vibrating sample magnetometer. We thank R. Erni for collaborating in the analysis of the diffraction measurements. We thank C. Vockenhuber for performing Rutherford backscattering measurements on GdFeCo and TbCo. This research was supported by the Swiss National Science Foundation (grant nos 200020_200465 and PZ00P2-179944) and the Swiss Government Excellence Scholarship (ESKAS no. 2018.0056). The PolLux end station was financed by the German Ministerium für Bildung und Forschung (BMBF) through contracts 05K16WED and 05K19WE2. The work by E.M. and V.R. was supported by the Ministerio de Economía y Competitividad of the Spanish Government (project no. MAT2017-87072-C4-1-P) and by the Consejería de Educación of the Junta de Castilla y Leon (project nos SA299P18 and SA0114P20). We acknowledge the Paul Scherrer Institut, Villigen, Switzerland for provision of synchrotron radiation beamtime at beamline X07DA-PolLux of the Swiss Light Source. We also thank the Helmholtz-Zentrum Berlin for the allocation of synchrotron radiation beamtime at the UE-46 Maxymus beamline

Strain-induced ferroelectricity and spin-lattice coupling in SrMnO3 thin films

Designing novel multiferroic materials with simultaneous ferroelectric and magnetic orders has been one of the focal points over the last decade due to the promising applications and rich physics involved. In this study, using epitaxial strain (up to 3.8%) as tuning knob, we successfully introduce multiferroicity with prominent high-temperature ferroelectricity into the paraelectric SrMn O 3 . More interestingly, the experimental temperature-dependent ferroelectric and magnetic studies suggest that the emergent antiferromagnetic order below 100 K greatly enhances the ferroelectric polarization due to the spin-order-induced ionic displacements. We envision that the strain-mediated spin-phonon coupling can be utilized as a pathway to discover functionalities in a wide range of antiferromagnetic insulators with delicate epitaxial manipulations