Mesoscovic magnetic/semiconductor heterostructures (2006)
Xu, Y.B., Ahmad, E., Lu, Y.X., Claydon, J.S., Zhai, Y.
We report the experimental results of Fe and Fe3O4 nanostructures on GaAs(100) surfaces and hybrid Ferromagnetic/Semiconductor/Ferromagnetic (FM/SC/FM) spintronic devices. Element specific x-ray...
Morley, N.A., Gibbs, M.R.J., Ahmad, E., Will, I.G., Xu, Y.B.
Thin epitaxial Fe films grown on GaAs(100) and Ga0.8In0.2As(100) substrates were investigated to determine how tuning the lattice constant mismatch between the Fe and the substrate may change the...
Annealing-induced Fe oxide nanostructures on GaAs (2005)
Lu, Y.X., Ahmad, E., Xu, Y.B., Thompson, S.M.
We report the evolution of Fe oxide nanostructures on GaAs(100) upon pre- and post-growth annealing conditions. GaAs nanoscale pyramids were formed on the GaAs surface due to wet etching and thermal...
Spin and orbital moments of ultra-thin Fe films on various semiconductor surfaces (2005)
Claydon, J.S., Niu, D.X., Xu, Y.B., Telling, N.D., Kirkman, I.W.
The magnetic moments of ultrathin Fe films on three different III-V semiconductor substrates, namely GaAs, InAs and In0.2Ga0.8As have been measured with X-ray magnetic circular dichroism at room...
XPS and XMCD study of Fe3O4/GaAs interface (2005)
Lu, Y.X., Claydon, J.S., Ahmad, E., Xu, Y.B., Thompson, S.M., Wilson, K., ...
Ultrathin Fe oxide films of various thicknesses prepared by post-growth oxidation on GaAs(100) surface have been investigated with X-ray photoelectron spectroscopy (NPS), X-ray absorption...
Vertical spinal electronic device with large room temperature magnetoresistance (2005)
Ahmad, E., Valavanis, A., Claydon, J.S., Lu, Y.X., Xu, Y.B.
We report experimental transport measurements of a vertical hybrid ferromagnetic (FM)/III-V semiconductor (SC)/ferromagnetic(FM) type structure, i.e., Cr(20ML)/Co(15ML)/GaAs(50 nm, n-type)/Al/sub...
Vertical spinal electronic device with large room temperature magnetoresistance (2005)
Ahmad, E., Valavanis, A., Claydon, J.S., Lu, Y.X., Xu, Y.B.
We report experimental transport measurements of a vertical hybrid ferromagnetic (FM)/III-V semiconductor (SC)/ferromagnetic(FM) type structure, i.e., Cr(20ML)/Co(15ML)/GaAs(50 nm, n-type)/Al/sub...
Hybrid Fe3O4/GaAs(100) structure for spintronics (2005)
Lu, Y.X., Claydon, J.S., Ahmad, E., Xu, Y.B., Ali, M., Hickey, B.J., ...
Fe3O4/GaAs hybrid structures have been studied using reflection high-energy electron diffraction (RHEED), x-ray photoelectron spectroscopy (XPS), x-ray magnetic circular dichroism (XMCD), and...
Epitaxial growth and magnetic properties of half-metallic Fe3O4 on GaAs(100) (2004)
Lu, Y.X., Claydon, J.S., Xu, Y.B., Thompson, S.M., Wilson, K.
The growth and magnetic properties of epitaxial magnetite Fe3O4 on GaAs(100) have been studied by reflection high-energy electron diffraction, x-ray photoelectron spectroscopy, magneto-optical Kerr...
A nonlinear current-voltage (I-V) characteristic was observed in patterned NiFe wires with a central "bow-tie" point contact constriction. By passing a dc current through the wire, a sharp resistance...
Xu, Y. B., Zhang, R. G., Joachimiak, A., Carr, P. D., Huber, T., Vasudevan, S. G., ...
We report the crystal structure of the N-terminal domain of Escherichia coli adenylyltransferase that catalyzes the reversible nucleotidylation of glutamine synthetase (GS), a key enzyme in nitrogen...
Interface magnetic properties of epitaxial Fe-InAs heterostructures (2002)
Xu, Y.B., Tselepi, M., Wu, J., Wang, S., Bland, J.A.C., Huttel, Y., ...
The growth and interface magnetic properties of epitaxial Fe films grown on InAs (100)-4 x 2 have been studied using low-energy electron diffraction, in situ magneto-optical Kerr effect, and X-ray...
Effects of interdot dipole coupling in mesoscopic epitaxial Fe(100) dot arrays (2001)
Xu, Y.B., Hirohata, A., Gardiner, S.M., Tselepi, M., Rothman, J., Klaui, M., ...
The domain structure and the coercivity of epitaxial Fe(100) circular dot arrays of different diameters and separations have been studied using magnetic force microscopy (MFM) and focused...
Suppression of 90° spin switching in Co nanomagnets grown on the Cu(110)-{2×1}O surface (2001)
Tselepi, M., Bode, P.J., Xu, Y.B., Wastlbauer, G., Hope, S., Bland, J.A.C.
We report on the effect of oxygen on the CO-induced 90° spin switching in the Co/Cu(110) system [Hope et al., Phys. Rev. B 57, 7454 (1998)]. The epitaxial fcc Co films were grown on the unsaturated...
Giant enhancement of orbital moments and perpendicular anisotropy in epitaxial Fe/GaAs(100) (2001)
Xu, Y.B., Tselepi, M., Guertler, C.M., Vaz, C.A.F., Wastlbauer, G., Bland, J.A.C., ...
The spin and orbital magnetic moments and the perpendicular magnetic anisotropy of 8 and 33 monolayer epitaxial bcc Fe films grown on GaAs(100)-4×6 have been measured using x-ray magnetic circular...
Magnetic Compton scattering study of the ferromagnetic amorphous alloys Fe1-xBx (2001)
Taylor, J.W., Duffy, J.A., Bebb, A.M., Cooper, M.J., Dugdale, S.B., McCarthy, J.E., ...
The boron contribution to the total spin moment in the amorphous alloys Fe1-xBx (x=0.2,0.24) has been determined using magnetic Compton scattering. The magnitude of the induced boron moment was...
Patterning ferromagnetism in Ni80Fe20 films via Ga+ ion irradiation (2001)
Kaminsky, W. M., Jones, G.A.C., Patel, N.K., Booij, W.E., Blamire, M.G., Gardiner, S.M., ...
We demonstrate that focused Ga+ ion irradiation can comprehensively modify the ferromagnetic properties of Ni80Fe20 thin films. Magneto-optic Kerr effect measurements at room temperature and...
Hirohata, A., Xu, Y.B., Guertler, C.M., Bland, J.A.C., Holmes, S.N.
Circularly polarized light was used to excite electrons with a spin polarization perpendicular to the film plane in 3 nm Au/5 nm Ni80Fe20/GaAs(100) structures with doping density in the range 10(23)...
Th structure of the P-II-ATP complex (2001)
Xu, Y. B., Carr, P. D., Huber, T., Vasudevan, S. G., Ollis, D. L.
P-II is a signal transduction protein that is part of the cellular machinery used by many bacteria to regulate the activity of glutamine synthetase and the transcription of its gene. The structure of...
Magnetization reversal in mesoscopic Ni80Fe20 wires: A magnetic domain launching device (2000)
Lee, W.Y., Hirohata, A., Leung, H.T., Guertler, C.M., Xu, Y.B., Gardiner, S.M., ...
The magnetization reversal process in mesoscopic permalloy (Ni80Fe20) wire structures has been investigated using scanning Kerr microscopy, magnetic force microscopy (MFM) and micromagnetic...
Magnetic domain studies of permalloy wire-based structures with junctions (2000)
Hirohata, A., Yao, C.C., Leung, H.T., Xu, Y.B., Guertler, C.M., Bland, J.A.C.
Permalloy (Ni-80 Fe-20) wire-based structures (30 nm thick and 1 . w . 10 mum wide) with junctions (crosses, networks, H-shapes, rectangular chains and ring chains) prepared on a GaAs (100) substrate...
Spin-polarized electron transport processes at the ferromagnet/semiconductor interface (2000)
Bland, J.A.C., Hirohata, A., Xu, Y.B., Guertler, C.M., Holmes, S.N.
Circularly polarized light was used to excite electrons with a spin polarization perpendicular to the film plane in ferromagnet/semiconductor hybrid structures. The Schottky characteristics at the...
Anisotropic lattice relaxation and uniaxial magnetic anisotropy in Fe/InAs(100)-4×2 (2000)
Xu, Y.B., Freedland, D.J., Tselepi, M., Bland, J.A.C.
The magnetic anisotropy and the lattice relaxation of epitaxial Fe films grown on InAs(100)-4×2 at room temperature have been studied using in situ magneto-optical Kerr effect and reflection...
Magnetoresistance of a domain wall at a submicron junction (2000)
Xu, Y.B., Vaz, C.A., Hirohata, A., Leung, H.T., Yao, C.C., Bland, J.A.C., ...
A local magnetoresistance (MR) effect associated with the switching of a coherent spin block confined in a cross-shaped junction of mesoscopic ferromagnetic NiFe wires was probed with the voltage...
Uniaxial magnetic anisotropy of epitaxial Fe films on InAs(100)-4×2 and GaAs(100)-4×2 (2000)
Xu, Y.B., Freedland, D.J., Tselepi, M., Bland, J.A.C.
The evolution of the uniaxial magnetic anisotropy of ultrathin epitaxial Fe films grown on InAs(100)-4×2 and GaAs(100)-4×2 has been studied in situ by means of the magneto-optical Kerr effect. In...
Micromagnetism in mesoscopic epitaxial Fe dot arrays (2000)
Xu, Y.B., Hirohata, A., Lopez-Diaz, L., Leung, H.T., Tselepi, M., Gardiner, S.M., ...
The domain structures of epitaxial Fe (20 nm)/GaAs(100) circular dot arrays (diameters from 50 to 1 µm) were studied with magnetic force microscopy. A transition from a single domain to a...
Xu, Y.B., Greig, D., Seddon, E.A., Matthew, J.A.D.
The partial spin-dependent densities of states (DOS) of both the iron and the boron in Fe–B amorphous magnetic alloys have been determined from spin-resolved photoemission using a synchrotron...
Domain nucleation processes in mesoscopic Ni80Fe20 wire junctions (2000)
Lee, W.Y., Yao, C.C., Hirohata, A., Xu, Y.B., Leung, H.T., Gardiner, S.M., ...
The magnetization reversal process in permalloy (Ni80Fe20) wire junction structures has been investigated using magnetoresistance (MR) measurements and scanning Kerr microscopy. A combination of...
Evidence for polarised boron in Co-B and Fe-B alloys (1999)
Xu, Y.B., Greig, D., Seddon, E.A., Cornelius, S., Matthew, J.A.D.
By exploiting the tunability of synchrotron radiation in measurements of spin-resolved photoemission it has proved possible to obtain information on the polarisation of the valence electrons of Co-B...
Pseudo-Hall effect and anisotropic magnetoresistance in a micronscale Ni80Fe20 device (1999)
Yao, C.C., Hasko, D.G., Lee, W.Y., Hirohata, A., Xu, Y.B., Bland, J.A.C.
The pseudo-Hall effect (PHE) and anisotropic magnetoresistance (AMR) in a micronscale Ni80Fe20, six-terminal device, fabricated by optical lithography and wet chemical etching from a high quality UHV...
Hirohata, A., Xu, Y.B., Guertler, C.R., Bland, J.A.C.
Circularly polarized light was used to excite electrons with a spin polarization perpendicular to the film plane in 3 nm Au/5 nm Co/GaAs (110) structures. At perpendicular saturation, the bias...
Magnetization reversal and magnetic anisotropy in Co network nanostructures (1999)
Lee, W.Y., Leung, H.T., Zhang, W., Xu, Y.B., Hirohata, A., Yao, C.C., ...
The magnetization reversal and magnetic anisotropy in Co network structures have been studied using magneto-optic Kerr effect (MOKE). An enhancement of the coercivity is observed in the network...
Yao, C.C., Hasko, D.G., Lee, W.Y., Hirohata, A., Xu, Y.B., Bland, J.A.C.
The magnetisation reversal processes and magnetoresistance behaviour in micron-sized Ni80Fe20 wires with triangular and rectangular modulated width have been studied. The wires were fabricated by...
Magnetic domain evolution in permalloy mesoscopic dots (1999)
Hirohata, A., Leung, H.T., Xu, Y.B., Yao, C.C., Lee, W.Y., Bland, J.A.C., ...
Permalloy (Ni80Fe20) squares (30 nm thick and w mu m wide; 1 less than or equal to w less than or equal to 200 mu m) and circular disks (30 nm thick and r mu m diameter; 1 less than or equal to r...
Ferromagnetic/III-V semiconductor heterostructures and magneto-electronic devices (1999)
Xu, Y.B., Freeland, D.J., Tselepi, M., Guertler, C.M., Lee, W.Y., Bland, J.A.C., ...
The interface magnetic and electronic properties of two Fe/III-V semiconductor systems, namely Fe/GaAs and Fe/InAs, grown at room temperature have been studied. A "magnetic interface", which is...
Single crystal Fe films grown on InAs(100) by molecular beam epitaxy (1998)
Xu, Y.B., Kernohan, E.T.M., Tselepi, M., Ercole, A., Bland, J.A.C., Holmes, S.
Thin Fe films have been grown on InAs(100) by molecular beam epitaxy, and studied using in situ magneto-optical Kerr effect (MOKE), low energy electron diffraction (LEED), and scanning tunneling...
Evolution of the ferromagnetic phase of ultrathin Fe films grown on GaAs(100)-4x6 (1998)
Xu, Y.B., Kernohan, E.T.M., Freedland, D.J., Ercole, A., Tselepi, M., Bland, J.A.C.
Epitaxial bcc Fe has been grown on GaAs(100)-(4×6) at room temperature and studied with in situ magneto-optical Kerr effect (MOKE), low-energy electron diffraction, and alternating gradient field...
Spin-resolved photoemission of in-situ sputtered iron and iron-yttrium alloys (1997)
Xu, Y.B., Greig, D., Seddon, E.A., Matthew, J.A.D.
Spin-resolved photoemission spectra of amorphous Fe-Y alloys have been obtained and compared with both those of pure Fe and with theoretical electronic structure calculations. The thin iron and alloy...
The spin-dependent electronic structure of amorphous magnetic alloys (1997)
Xu, Y.B., Greig, D., Mitchell, A.L., Seddon, E.A., Matthew, J.A.D.
Spin-resolved photoemission from FeB and CoB binary amorphous alloys has been measured using, for the first time, a synchrotron radiation source. A comparison of the experimental results with several...