Browsing Physics (Scholarly Publications) by Author "RODE, KARSTEN"
Now showing items 1-20 of 20
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Boron diffusion in magnetic tunnel junctions with MgO (001) barriers and CoFeB electrodes
KURT, HUSEYIN; OGUZ, KAAN; BOESE, MARKUS; FAULKNER, COLM; COEY, JOHN; RODE, KARSTEN (2010)Boron diffusion out of the CoFeB layers in model systems with thick CoFeB and MgO layers grown by radiofrequency sputtering or electron-beam evaporation and in MgO-based magnetic tunnel junctions (MTJs) is probed after ... -
Cubic Mn 2 Ga Thin films: Crossing the spin gap with ruthenium
COEY, JOHN; VENKATESAN, MUNUSWAMY; RODE, KARSTEN; STAMENOV, PLAMEN (2014)Cubic Mn2Ga films with the half-Heusler C1b structure are grown on V (001) epitaxial films. The phase is a soft ferrimagnet, with Curie temperature TC = 225 K and magnetization Ms=280 kA m−1, equivalent to 1.65μB per ... -
Designing a fully compensated half-metallic ferrimagnet
SANVITO, STEFANO; COEY, JOHN; RODE, KARSTEN (2016)Recent experimental work on Mn 2 Ru x Ga demonstrates its potential as a compensated ferrimagnetic half metal (CFHM). Here we present a set of high-throughput ab initio density functional theory calculations and a ... -
Exchange-biased magnetic tunnel junctions with antiferromagnetic epsilon-Mn3Ga
RODE, KARSTEN; VENKATESAN, MUNUSWAMY; STAMENOV, PLAMEN; COEY, JOHN (2012)Oriented c-axis films of the hexagonal triangular antiferromagnetic ?-Mn3Ga have been used in bottom-pinned synthetic antiferromagnetmagnetic tunnel junctions with MgO barriers, which show up to 150% tunneling magnetoresistance ... -
Giant spontaneous Hall effect in zero-moment Mn2Ru x Ga
RODE, KARSTEN; COEY, JOHN; STAMENOV, PLAMEN; BORISOV, KIRIL; LAU, YONG; BETTO, DAVIDE (2015)Spin-dependent transport properties of Mn2Ru x Ga thin-films are studied as function of the Ru concentration and the substrate-induced strain. The large spontaneous Hall angle of 7.7% twenty times bigger than in other 3d ... -
High spin polarization in epitaxial films of ferrimagnetic Mn3Ga
COEY, JOHN; VENKATESAN, MUNUSWAMY; RODE, KARSTEN; STAMENOV, PLAMEN (2011)Ferrimagnetic Mn3Ga exhibits a unique combination of low saturation magnetization (Ms=0.11 MA m−1) and high perpendicular anisotropy with a uniaxial anisotropy constant of Ku = 0.89 MJ m−3. Epitaxial c-axis films exhibit ... -
Investigation on the origin of the magnetic moment of BiFeO3 thin films by advanced x-ray characterizations
RODE, KARSTEN (2006)Single phase 001 -oriented BiFeO 3 BFO thin films grown by pulsed laser deposition can only be obtained in a narrow window of deposition pressure and temperature and have a low magnetic moment. Out of ... -
Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes
COLEMAN, JONATHAN; NICOLOSI, VALERIA; RODE, KARSTEN; NERL, HANNAH; POKLE, ANUJ; DUESBERG, GEORG; MCEVOY, NIALL (2016)We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines ... -
Magnetic and electronic properties of D022-Mn3Ge (001) films
RODE, KARSTEN; SANVITO, STEFANO; COEY, JOHN; STAMENOV, PLAMEN; VENKATESAN, MUNUSWAMY (2012)Oriented thin films of Mn3Ge with the tetragonal D022structure,grown on strontium titanate substrates, exhibit a low magnetization M s?=?73?kA m?1 combined with high uniaxial anisotropyK u?=?0.91?MJ m?3 at 300?K, making ... -
Magnetic, transport, and structural properties of SrRuO3 thin films
STAMENOV, PLAMEN; COEY, JOHN; RODE, KARSTEN (2014)Thin films of the oxide ferromagnetic metal SrRuO3 (SRO) are studied, in view of their potential use within oxide-based spin electronic devices. Here, their epitaxial growth on Si-compatible SrTiO3 substrates is demonstrated ... -
Magnetism of (Zn,Co)O thin films probed by x-ray absorption spectroscopies
RODE, KARSTEN (2008)We report on the electronic and magnetic properties of Co-doped ZnO thin films investigated by x-ray absorption spectroscopies and element selective magnetometry. For a low Co concentration (around 5%), we evidence a ... -
Magnetization processes in micron-scale (CoFe/Pt)(n) multilayers with perpendicular anisotropy: First-order reversal curves measured by extraordinary Hall effect
RODE, KARSTEN; COEY, JOHN; STAMENOV, PLAMEN (2012)First-order reversal curves (FORCs) were recorded using the extraordinary Hall effect in micron-sized crosses of [Co90Fe10 (0.5?nm)/Pt (1.0?nm)] n multilayers with n?=?10, 20, and 50, which exhibit perpendicular magnetic ... -
Nanometer scale mapping of cobalt in Al-doped ferromagnetic Zn 0.7Co0.3O thin film
RODE, KARSTEN (2006)There has been a renewed interest in zinc oxide in the materials science community after it was shown to be ferromagnetic when doped with cobalt. However, it has remained difficult to tell whether the origin of the ... -
Narrow-band tunable terahertz emission from ferrimagnetic Mn<inf>3-x</inf>Ga thin films
COEY, JOHN; RODE, KARSTEN (2016)Narrow-band terahertz emission from coherently excited spin precession in metallic ferrimagnetic Mn3-xGa Heusler alloy nanofilms has been observed. The efficiency of the emission, per nanometer film thickness, is comparable ... -
Perpendicular Magnetic Anisotropy in CoFeB/Pd Bilayers
COEY, JOHN; FOWLEY, CIARAN; OGUZ, KAAN; RODE, KARSTEN; KURT, HUSEYIN (2010)Perpendicular magnetic anisotropy is observed in ultrathin (0.6 nm) amorphous Co40Fe40B20 when sputtered on an MgO (001) buffer layer and capped with Pd. The layers are superparamagnetic with a blocking temperature of ... -
Site-specific magnetism of half-metallic Mn2RuxGa thin films determined by x-ray absorption spectroscopy
BETTO, DAVIDE; LAU, YONG; RODE, KARSTEN; COEY, JOHN; STAMENOV, PLAMEN (2015)The site-specific magnetic properties of thin films of the Heusler compound Mn2RuxGa, 0.6 <x< 1.0, are studied using x-ray absorption and dichroism spectroscopy. There is evidence of half metallicity up to x = 0.7, and ... -
Site-specific order and magnetism in tetragonal Mn3Ga thin films
STAMENOV, PLAMEN; COEY, JOHN; RODE, KARSTEN; SANVITO, STEFANO; VENKATESAN, MUNUSWAMY (2013)Mn 3 Ga bulk material and thin films deposited on several different substrates have been investigated using x-ray and neutron diffraction, x-ray absorption spectroscopy, x-ray magnetic circular dichroism, and ... -
Structure, site-specific magnetism, and magnetotransport properties of epitaxial D022 -structure Mn2FexGa thin films
STAMENOV, PLAMEN; COEY, JOHN; RODE, KARSTEN (2017) -
Tunnelling magnetoresistance of the half-metallic compensated ferrimagnet Mn<inf>2</inf>Ru<inf>x</inf>Ga
COEY, JOHN; STAMENOV, PLAMEN; RODE, KARSTEN (2016)Tunnel magnetoresistance ratios of up to 40% ar e measured between 10 K and 300 K when the highly spin-polarized compensated ferrimagnet, Mn 2 Ru x Ga, is integrated into MgO-based perpendicular magnetic tunnel ... -
The zero-magnetization Heusler ferrimagnet
COEY, JOHN; VENKATESAN, MUNUSWAMY; RODE, KARSTEN; ACKLAND, KARL (2013)An unusual zero-moment half-metallic state has been predicted in stoichiometric Heusler compounds with 24 valence electrons, where, unlike an antiferromagnet, the two sublattices are chemically or crystallographically ...