Electrical Detection of DC Spin Current Propagation Through an Epitaxial Antiferromagnetic NiO Layer

This is the author accepted manuscript. The final version is available from IEEE via the DOI in this recordA method for detecting dc spin current propagation through an epitaxial antiferromagnetic (AFM) NiO layer is presented. Spin current is generated by spin pumping from an adjoining ferromagnetic (FM) layer and detected in a non-magnetic metallic layer by the inverse spin Hall effect. Comparison is made with a YIG/Pt bilayer, where only the Pt layer is electrically conducting, but for which spin Hall magnetoresistance makes an additional contribution to the measured signal. The signal obtained from the multilayered stack containing the AFM NiO layer is found to contain additional contributions due to anisotropic magnetoresistance. By exciting the sample with out-of-plane rf magnetic field and making measurements with a static field applied at different orientations within the plane of the sample, a signal associated with the dc spin current may be identified.Engineering and Physical Sciences Research Council (EPSRC

Climate Change, Habitat Loss, Protected Areas and the Climate Adaptation Potential of Species in Mediterranean Ecosystems Worldwide

Mediterranean climate is found on five continents and supports five global biodiversity hotspots. Based on combined downscaled results from 23 atmosphere-ocean general circulation models (AOGCMs) for three emissions scenarios, we determined the projected spatial shifts in the mediterranean climate extent (MCE) over the next century. Although most AOGCMs project a moderate expansion in the global MCE, regional impacts are large and uneven. The median AOGCM simulation output for the three emissions scenarios project the MCE at the end of the 21st century in Chile will range from 129–153% of its current size, while in Australia, it will contract to only 77–49% of its current size losing an area equivalent to over twice the size of Portugal. Only 4% of the land area within the current MCE worldwide is in protected status (compared to a global average of 12% for all biome types), and, depending on the emissions scenario, only 50–60% of these protected areas are likely to be in the future MCE. To exacerbate the climate impact, nearly one third (29–31%) of the land where the MCE is projected to remain stable has already been converted to human use, limiting the size of the potential climate refuges and diminishing the adaptation potential of native biota. High conversion and low protection in projected stable areas make Australia the highest priority region for investment in climate-adaptation strategies to reduce the threat of climate change to the rich biodiversity of the mediterranean biome

Temperature dependence of spin Hall magnetoresistance in thin YIG/Pt films

We report on the temperature dependence of the recently discovered spin Hall magnetoresistance in a yttrium iron garnet (YIG)/platinum (Pt) thin film. The YIG/Pt layers are an ideal choice as the combination of an insulating magnetic material and the high spin-orbit interaction in Pt gives a relatively large magnetoresistance and no electrical conduction occurs in the YIG. The temperature dependence of the magnetoresistance was measured between 1.4 K and 280 K from which the temperature dependence of the spin diffusion length in Pt has been extracted. We found that the best agreement between our data and the recently published [Chen, Phys. Rev. B 87, 144411 (2013)PRBMDO1098-012110.1103/ PhysRevB.87.144411] theory of the spin Hall magnetoresistance is given by an assumed Elliot-Yafet mechanism of spin relaxation with temperature-independent spin Hall angle and spin mixing conductance. The best estimate for the spin diffusion length returns values between 0.57 and 3.85 nm