Sidewall depletion in nano-patterned LAO/STO heterostructures

We report the fabrication of nanostructures from the quasi-two-dimensional electron gas (q2DEG) formed at the LaAlO$_{3}$/ SrTiO$_{3}$ (LAO/STO) interface. The process uses electron beam lithography in combination with reactive ion etching. This technique allows to pattern high-quality structures down to lateral dimensions as small as $100$nm while maintaining the conducting properties without inducing conductivity in the STO substrate. Temperature dependent transport properties of patterned Hall bars of various widths show only a small size dependence of conductivity at low temperature as well as at room temperature. The deviation can be explained by a narrow lateral depletion region. All steps of the patterning process are fully industry compatible.Comment: 5 pages, 4 figure

Spin pumping and inverse spin Hall effect in ultrathin SrRuO₃ films around the percolation limit

We demonstrate spin pumping and inverse spin Hall effect (ISHE) in an all oxide heterostructure composed of two oxides with different respective crystal structures. Y3Fe5O12 (YIG) is used as a spin source, being a perfect candidate because of its low damping and insulating behavior. SrRuO3 (SRO), a perovskite oxide with metallic conductivity, serves as a spin sink. Spin pumping is shown by the increase of the damping in ferromagnetic resonance for the YIG in the presence of an SRO top layer and by the inverse spin Hall effect appearing in the SRO. Transmission electron microscopy shows that the growth of YIG is fully epitaxial, while the SRO grows in islands of several polycrystaline phases, a fact which strongly influences the measured ISHE. The magnetization of the YIG remains unaffected by the SRO layer while the SRO no longer shows the low temperature ferromagnetism typically observed in monocrystalline layers

Phil. Mag.

Spark-plasma sintering of oxide ceramics is shown to be capable of provoking internal strain. This finding, which in terms of materials design is invaluable, is based on an in-depth analysis of the Ti-L-2,L-3 and O-K electron energy-loss near-edge structure of Ba2TiSi2O8 acquired in a dedicated scanning transmission electron microscope. The electronic structure of Ba2TiSi2O8 as probed by electron energy loss spectroscopy proved particularly sensitive to distortions of the titanium and oxygen environment.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000249890700007&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Materials Science, MultidisciplinaryMechanicsMetallurgy & Metallurgical EngineeringPhysics, AppliedPhysics, Condensed MatterSCI(E)EI1ARTICLE294555-45668