Department of Physics and Astronomy
156 Behlen Laboratory
Phone: (402) 472-0180
Email: rskomski2@unl.edu
The research of Ralph Skomski focuses on theory of magnetic nanostructures. The main aim is to model the behavior of nanostructures and to make predictions about conceivable but difficult-to-produce materials. The relevant length scales of the involved structural features vary from a few interatomic distances to more than 100 nm, and each length scale has its own characteristics. Examples of small-scale magnetic nanostructures of interest are nanotubes, nanorings, patterned thin films, and particulate materials. These structures exhibit, among other features, interesting spin-wave and magnetization-reversal modes. On an atomic scale, chemical substitutions, interstitial modification, and changes in the crystal structure are exploited to tailor intrinsic properties such as anisotropy, Curie temperature and magnetic moment. On length scales larger than a few nm, the magnetic material can be treated as a continuum. In this regime, the atomic properties enter the consideration as micromagnetic parameters. The morphological peculiarities of magnetic nanostructures lead to a variety of novel micromagnetic effects. One example is intergranular exchange coupling, which has a strong effect on the performance of advanced permanent magnets, magnetic recording media, and magnetoresistive materials.
Other research areas of interest are time-dependent magnetization processes (magnetic viscosity and fast processes), the spin structure of half-metallic ferromagnets as well as topics such as RKKY interactions between nanomagnets embedded in a nonmagnetic metallic matrix. Emphasis is on analytic models, which are designed to complement and guide other scientists' numerical approaches, such as band-structure calculations.
2001
Layer-resolved spin polarization in Sb overlayers on NiMnSb, Ralph Skomski, T. Komesu, C.N. Borca, H.-K. Jeong, Peter A. Dowben, D. Ristoiu, and J.P. Nozie´res
Cooperative freezing in spin glasses and magnetic nanostructures, Ralph Skomski and Diandra Leslie-Pelecky
Cooperative magnetism and the Preisach model, Ralph Skomski and David J. Sellmyer
Grain-boundary micromagnetism, Ralph Skomski, H. Zeng, and David J. Sellmyer
Magnetic nanodot arrays produced by direct laser interference lithography, M. Zheng, M. Yu, Yi Liu, Ralph Skomski, Sy_Hwang Liou, David J. Sellmyer, V.N. Petryakov, Yu K. Verevkin, N.I. Polushkin, and N. N. Salashchenko
Ferromagnetic Co-C nanodot arrays produced by direct interferometric laser annealing, M. Zheng, M. Yu, Yi Liu, Ralph Skomski, David J. Sellmyer, V.N. Petryakov, Yu. K. Verevkin, Nikolay Polushkin, and N.N. Salashchenko
Coercivity of titanium-substituted high-temperature permanent magnets, Jian Zhou, Ralph Skomski, and David J. Sellmyer
2000
Temperature dependence of magnetic hysteresis of RCox:Co nanocomposites (R=Pr and Sm), J.P. Liu, Ralph Skomski, Yi Liu, and David J. Sellmyer
Hysteresis-loop overskewing in the light of a novel nucleation mode, Ralph Skomski, J.P. Liu, and David J. Sellmyer
Curie temperature of multiphase nanostructures, Ralph Skomski and David J. Sellmyer
Magnetic localization in transition-metal nanowires, Ralph Skomski, H. Zeng, M. Zheng, and David J. Sellmyer
Magnetic properties of self-assembled Co nanowires of varying length and diameter, H. Zeng, M. Zheng, Ralph Skomski, David J. Sellmyer, Yi Liu, L. Menon, and S. Bandyopadhyay
Sm–Co–Cu–Ti high-temperature permanent magnets, Jian Zhou, Ralph Skomski, C. Chen, G.C. Hadjipanayis, and David J. Sellmyer
1999
High Energy Products in Exchange-Coupled Nanocomposite Films, J.P. Liu, Yi Liu, Ralph Skomski, and David J. Sellmyer
Magnetic hardening in SmCox–Co multilayers and nanocomposites, J.P. Liu, Yi Liu, Ralph Skomski, and David J. Sellmyer
RKKY interactions between nanomagnets of arbitrary shape, Ralph Skomski
Activation entropy, activation energy, and magnetic viscosity, Ralph Skomski, Roger D. Kirby, and David J. Sellmyer
Quasicoherent nucleation mode in two-phase nanomagnets, Ralph Skomski, J.P. Liu, and David J. Sellmyer
1998
Higher-order and next-nearest-neighbor Néel anisotropies , Y.T. Millev, Ralph Skomski, and J. Kirschner
Finite-temperature behavior of anisotropic two-sublattice magnets, Ralph Skomski
Magnetoelectric Néel anisotropies, Ralph Skomski
Micromagnetic localization, Ralph Skomski
Micromagnetics of ultrathin films with perpendicular magnetic anisotropy , Ralph Skomski, H.-P. Oepen, and J. Kirschner
Unidirectional anisotropy in ultrathin transition-metal films , Ralph Skomski, H.-P. Oepen, and J. Kirschner
Iron and nickel surface and interface anisotropies, Ralph Skomski, D. Sander, C. Schmidthals, A. Enders, and J. Kirschner
Immobilization diffusion in R2Fe17 nitrides, Ralph Skomski and S. Wirth
Hydrogen in R2Fe17 intermetallic compounds: Structural, thermodynamic, and magnetic properties, S. Wirth, Ralph Skomski, and J.M.D. Coey
1997
Magnetism and morphology of Fe/Cu(111) films below two-dimensional percolation, J. Shen, Ralph Skomski, M. Klaua, H. Jenniches, S. Sundar Manoharan, and J. Kirschner
Magnetism in one dimension: Fe on Cu(111) , J. Shen, Ralph Skomski, M. Klaua, H. Jenniches, S. Sundar Manoharan, and J. Kirschner
Domain-wall curvature and coercivity in pinning type Sm–Co magnets, Ralph Skomski
Superparamagnetic ultrathin films, Ralph Skomski, D. Sander, J. Shen, and J. Kirschner
1996
High coercive Field and Film Stress for epitaxial Monolayers of Fe on W(110), D. Sander, A. Enders, Ralph Skomski, and J. Kirschner
Film Stress and Domain Wall Pinning in Sesquilayer Iron Films on W(110), D. Sander, Ralph Skomski, C. Schmidthals, A. Enders, and J. Kirschner
The Itinerant Limit of Metallic Anisotropy, Ralph Skomski
An Effective-Viscosity Description of Domain-Wall Motion in Magnetic Thin Films with Perpendicular Anisotropy, Ralph Skomski, J. Giergiel, and J. Kirschner
Is there Spin-Glass Exchange in Ultrathin Fe(110) Films ?, Ralph Skomski, D. Sander, A. Enders, and J. Kirschner
Determination of crystal-field parameters of Sm2Fe17N3 and Sm2Fe17C3, S. Wirth, M. Wolf, K.H. Muller, Ralph Skomski, S. Brennan, and J.M.D. Coey
1994
NON-EQUILIBRIUM GAS-PHASE NITROGENATION, S. Brennan, Ralph Skomski, and J.M.D. Coey
Magnetoresistance in Nanostructured Co-Ag Prepared by Mechanical- Alloying, J.M.D. Coey, A.J. Fagan, Ralph Skomski, J. Gregg, K. Ounadjela, and S.M. Thompson
Magnetoresistance in Nanostructured Co-Ag Prepared by Mechanical- Alloying, J.M.D. Coey, A.J. Fagan, Ralph Skomski, J. Gregg, K. Ounadjela, and S.M. Thompson
Aligned two-phase magnets: Permanent magnetism of the future? (invited), Ralph Skomski
Exchange Coupling and Energy Product in Random Two- Phase Aligned Magnets, Ralph Skomski and J.M.D. Coey
1993
New Magnets from Interstitial Intermetallics, J.M.D. Coey and Ralph Skomski
Characterization, transport, and magnetic properties of Co/Pd multilayers produced by pulsed laser deposition, M. Enrech, Ralph Skomski, J.M.D. Coey, and J.G. Lunney
Giant energy product in nanostructured two-phase magnets , Ralph Skomski and J.M.D. Coey
Nitrogen diffusion in Sm2Fe17 and local elastic and magnetic properties, Ralph Skomski and J.M.D. Coey
NUCLEATION FIELD AND ENERGY PRODUCT OF ALIGNED TWO-PHASE MAGNETS - PROGRESS TOWARDS THE '1 MJ/m3' MAGNET, Ralph Skomski and J.M.D. Coey
Crystal field in nitrogenated rare-earth intermetallics, Ralph Skomski, M.D. Kuz'min, and J.M.D. Coey
Magnetic reversal in Sm2Fe17Ny permanent magnets, Ralph Skomski, K.-H. Müller, P.A.P. Wendhausen, and J.M.D. Coey
Interstitial modification of rare-earth intermetallics, Ralph Skomski, S. Murray, S. Brennan, and J.M.D. Coey
On the role of Zn in Sm2Fe17Nx permanent magnets, P.A.P. Wendhausen, D. Eckert, A. Handstein, K.-H. Müller, G. Leitner, and Ralph Skomski
1992
GAS PHASE INTERSTITIAL MODIFICATION OF RARE-EARTH INTERMETALLICS, J.M.D. Coey, Ralph Skomski, and S. Wirth
Magnetization and 57Fe hyperfine fields in Y2Fe17Z3- δ (Z=H, C, or N) interstitial compounds, Qi-nian Qi, Hong Sun, Ralph Skomski, and J.M.D. Coey