Physics (Scholarly Publications): Recent submissions

Now showing items 381-400 of 1742

    • Determination of bulk domain structure and magnetization processes in bcc ferromagnetic alloys: Analysis of magnetostriction in Fe83Ga17 

      Coey, John; He, Yangkun; Schaefer, Rudolf; Jiang, Chengbao (2018)
      The ground state of macroscopic samples of magnetically ordered materials is a domain state because of magnetostatic energy or entropy, yet we have limited experimental means for imaging the bulk domain structure and the ...

    • d-zero Magnetism in Nanoporous Amorphous Alumina Membranes 

      Coey, John; Esmaeily, Amir Sajad; Venkatesan, M.; Sen, S. (2018)
      Nanoporous alumina membranes produced by mild or hard anodisation in oxalic acid at potentials ranging from 5 – 140 V have a controllable pore surface area of up to 200 times the membrane area. They exhibit a saturating ...

    • Magnetocrystalline anisotropy and exchange probed by high-field anomalous Hall effect in fully compensated half-metallic Mn2RuxGa thin films 

      Coey, John; Stamenov, Plamen; Rode, Karsten; Atcheson, Gwenael (2018)
      Magnetotransport is investigated in thin films of the half-metallic ferrimagnet Mn2RuxGa in pulsed magnetic fields of up to 58 T. A nonvanishing Hall signal is observed over a broad temperature range, spanning the compensation ...

    • Oxygen Electromigration and Energy Band Reconstruction Induced by Electrolyte Field Effect at Oxide Interfaces 

      Coey, John; Zeng, S.W.; Yin, X.M.; Herng, T.S.; Han, K.; Huang, Z.; Zhang, L.C.; Li, C.J.; Zhou, W.X.; Wan, D.Y.; Yang, P.; Ding, J.; Wee, A.T.S.; Venkatesan, T.; Rusydi, A.; Ariando, A. (2018)
      Electrolyte gating is a powerful means for tuning the carrier density and exploring the resultant modulation of novel properties on solid surfaces. However, the mechanism, especially its effect on the oxygen migration and ...

    • Spin-phonon coupling parameters from maximally localized Wannier functions and first-principles electronic structure: Single-crystal durene 

      Sanvito, Stefano; Roychoudhury, Subhayan (2018)
      Spin-orbit interaction is an important vehicle for spin relaxation. At finite temperature lattice vibrations modulate the spin-orbit interaction and thus generate a mechanism for spin-phonon coupling, which needs to be ...

    • Optics In Ireland 

      Bradley, Louise; Leahy, Martin; Riza, Nabeel A.; Sheridan, John T. (Optical Society of America, 2018)
      This feature issue provides a snapshot of some of the applied optics and photonics related research and development activities currently taking place across Ireland. The issue contains some thirty papers, including ...

    • Theory of rotational columnar structures of soft spheres 

      Hutzler, Stefan; Weaire, Denis; Winkelmann, J.; Mughal, A.; Williams, D.B. (2019)
      There is a growing interest in cylindrical structures of hard and soft particles. A promising new method to assemble such structures has recently been introduced by Lee et al. [T. Lee, K. Gizynski, and B. Grzybowski, ...

    • Antiferromagnetic single-layer spin-orbit torque oscillators 

      Stamenov, Plamen; Rode, Karsten; Coey, John (2019)
      We show how a charge current through a single antiferromagnetic layer can excite and control self-oscillations. Sustained oscillations with tunable amplitudes and frequencies are possible in a variety of geometries using ...

    • Neutron imaging of liquid-liquid systems containing paramagnetic salt solutions 

      BUTCHER, TIM ALEXANDER (2019)
      The method of neutron imaging was adopted to map the concentration evolution of aqueous paramagnetic Gd(NO3)3 solutions. Magnetic manipulation of the paramagnetic liquid within a miscible nonmagnetic liquid is possible ...

    • Photonic molecules modes in resonantly coupled spherical microcavities with semiconductor nanocrystals 

      Bradley, Louise; Donegan, John; Rakovich, Yury; Gerlach, Matthias; Connolly, T.; Boland, J.J.; Gaponik, Nikolai; Rogach, A.L. (2005)
      We present a detailed study of the localized coupled-cavity modes in a photonic molecule formed from two dielectric spherical microcavities with CdTe nanocrystals, which show a multi-peak narrowband modal structure resulting ...

    • Room-temperature ultraviolet luminescence from g-CuCl on silicon 

      Bradley, Louise; O'Reilly, Lisa; Lucas, Olabanji; McNally, Patrick; Reader, Alec; Natarajan, Gomathi; Daniels, Stephen; Cameron, David C.; Mitra, Anirban; Martinez-Rosas, Miguel (2005)
      We have probed the luminescence properties of a wide-band-gap, direct band-gap optoelectronic material, grown on closely lattice-matched silicon substrates, namely, γ-CuCl on Si. This material system is compatible with ...

    • Interaction of Surface Plasmons with CdTe quantum dot excitons 

      Lunney, James; Donegan, John; Bradley, Louise; Donnelly, Tony; Vamsi, Komarala; Rakovich, Yury; Doggett, B.; Gaponik, Nikolai; Susha, A. (2005)
      A 5-fold enhancement in the luminescence of CdTe nanocrystal quantum dots (QDs) is observed when they are placed in proximity to a nanostructured Au film deposited by pulsed laser deposition technique. No enhancement is ...

    • Experimental analysis of polarization dependence of ultrafast gain dynamics in SOAs 

      Bradley, Louise; Kennedy, B.F.; Landais, Pascal (2005)
      Nonlinear polarization rotation in semiconductor optical amplifiers has been the focus of a lot of work in the past decade. A lot of research has been devoted to this phenomenon due to its possible use in all-optical ...

    • Dynamic Pump-probe studies of TE and TM modes in semiconductor optical amplfiers 

      Bradley, Louise; Philippe, Severine; Landais, Pascal; Martinez-Rosas, Miguel; Surre, Frederick (2005)
      A contra-propagation set up is implemented and dynamic pump probe studies of a InGaAsP/InP SOA in the gain regime are undertaken using pulses of 2ps duration. The time resolved amplified probe signal is measured separately ...

    • The use of wide-bandgap CuCl on silicon for ultra-violet photonics 

      Bradley, Louise; O'Reilly, Lisa; Natarajan, Gomathi; McNally, Patrick; Daniels, Stephen; Lucas, Olabanji; Mitra, Anirban; Martinez-Rosas, Miguel; Reader, Alec; Cameron, David C. (2005)
      γ-CuCl is a wide-bandgap (Eg = 3.395eV), direct bandgap, semiconductor material with a cubic zincblende lattice structure. Its lattice constant, aCuCl = 0.541 nm, means that the lattice mismatch to Si (aSi = 0.543 nm) is ...

    • Structural and optoelectronic properties of sputtered copper(I) chloride 

      Bradley, Louise; Natarajan, Gomathi; O'Reilly, Lisa; Daniels, Stephen; Cameron, David C.; McNally, Patrick; Lucas, Olabanji; Reader, Alec; Mitra, Anirban (2005)
      Copper (I) Chloride is a wide band gap semiconductor with great potential for silicon-based optoelectronics due to the fact that is closely lattice matched with silicon. This work examines the deposition of CuCl thin films ...

    • Origin of power fluctuations in GaN resonant-cavity light-emitting diodes 

      Bradley, Louise; Roycroft, Brendan; Akhter, Mahbub; Maaskant, Pleun; Corbett, Brian; Shaw, Alan; de Mierry, Phillipe; Poisson, Marie-Antoinette (2004)
      Resonant-cavity light-emitting diodes (RCLEDs) with multiple InGaN/GaN quantum wells have been grown on sapphire substrates. The emission was through the substrate, and the top contact consisted of a highly reflecting Pd/Ag ...

    • Machine learning density functional theory for the Hubbard model 

      Sanvito, Stefano; Tiwari, Rajarshi (2019)
      The solution of complex many-body lattice models can often be found by defining an energy functional of the relevant density of the problem. For instance, in the case of the Hubbard model the spin-resolved site occupation is ...

    • Nontrivial spatial dependence of the spin torques in L10 FePt-based tunneling junctions 

      Sanvito, Stefano; Galante, Mario; Ellis, Matthew O.A. (2019)
      We present an ab initio study of the spin-transfer torque in Fe/MgO/FePt/Fe magnetic tunnel junctions. We consider an FePt film with a thickness up to six unit cells, either in direct contact with the MgO spacer or with ...

    • Search for alternative magnetic tunnel junctions based on all-Heusler stacks 

      Sanvito, Stefano; Rotjanapittayakul, Worasak; Prasongkit, Jariyanee; Rungger, Ivan; Pijitrojana, Wanchai; Archer, Thomas (2018)
      By imposing the constraints of structural compatibility, stability, and a large tunneling magneto-resistance, we have identified the Fe3Al/BiF3/Fe3Al stack as a possible alternative to the well-established FeCoB/MgO/FeCoB ...