Research Associate Professor

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.

2009

Magnetic Correlations in Nanocomposite FePt:Au and FePt:C Films, Thomas A. George, Ralph Skomski, and David J. Sellmyer

Magnetism of FePt Surface Alloys, J. Honolka, T. Y. Lee, K. Kuhnke, Axel Enders, Ralph Skomski, S. Bornemann, S. Mankovsky, J. Minar, J. Staunton, H. Ebert, M. Hessler, K. Fauth, G. Schutz, A. Buchsbaum, M. Schmid, P. Varga, and K. Kern

Graded Permanent Magnets, Ralph Skomski, J. Hadjipanayis, and David J. Sellmyer

Dzyaloshinski–Moriya Micromagnetics of Magnetic Surface Alloys, Ralph Skomski, J. Honolka, S. Bornermann, H. Ebert, and Axel Enders

Magnetism of TiO and TiO2 Nanoclusters, Xiaohui Wei, Ralph Skomski, Balamurugan Balasubramanian, Z. G. Sun, Stephen Ducharme, and David J. Sellmyer

2008

The local environment of Co in B5CHx, Peter Dowben, A. Yu. Ignatov, Jing Lui, and Ralph Skomski

Nanostructure and magnetic properties of L10 FePt:X films, Thomas A. George, Zhen Li, Minglang Yan, Yingfan Xu, Ralph Skomski, and David Sellmyer

Temperature dependence of half-metallic hybridization gaps, Ralph Skomski

Temperature- and field-induced entropy changes in nanomagnets, Ralph Skomski, Christian Binek, T. Mukherjee, Sarbeswar Sahoo, and David J. Sellmyer

Nucleation and wall motion in graded media, Ralph Skomski, Thomas A. George, and David J. Sellmyer

Hysteresis of ultrasmall Fe–Pt particles, Ralph Skomski, J. P. Liu, C. B. Rong, and David J. Sellmyer

Band-structure and correlation effects in the Co(111) planes of CoO, Ralph Skomski, Xiaohui Wei, and David J. Sellmyer

Substrate-controlled growth and magnetism of nanosize Fe clusters on Pt, Ralph Skomski, J. Zhang, V. Sessi, J. Honolka, K. Kern, and Axel Enders

Proteresis in Co:CoO core-shell nanoclusters, X.-H. Wei, Ralph Skomski, Zhiguang Sun, and David Sellmyer

Ordered Layers of Co Clusters on BN Template Layers, J. Zhang, V. Sessi, C. H. MIchaelis, I. Brihuega, J. Honolka, K. Kern, Ralph Skomski, X. Chen, G. Rojas, and Axel Enders

2007

Coupled precession modes in indirect exchange-coupled [Pt/Co]–Co thin films, Steven Michalski, Jian Zhou, Ralph Skomski, and Roger D. Kirby

Surface anisotropy and magnetic freezing of MnO nanoparticles, Marco Morales Torres, Ralph Skomski, Shannon Fritz, G. Shelburne, Jeffrey E. Shield, Ming Yin, Stephen O'Brien, and Diandra Leslie-Pelecky

Structural phase transition and ferromagnetism in monodisperse 3 nm FePt particles, Chuan-bing Rong, Narayan Poudyal, Girija S. Chaubey, Vikas Nandwana, Ralph Skomski, Y. Q. Wu, M. J. Kramer, and J. Ping Liu

Finite-temperature depolarization in half metals, Ralph Skomski

Phase formation in L1 0 magnets, Ralph Skomski

Role of thermodynamic fluctuations in magnetic recording (invited), Ralph Skomski

Effective Demagnetizing Factors of Complicated Particle Mixtures, Ralph Skomski, G. C. Hadjipanayis, and David J. Sellmyer

Magnetic impurities in magic-number clusters, Ralph Skomski and David J. Sellmyer

Magnetization Reversal in Cubic Nanoparticles With Uniaxial Surface Anisotropy, Ralph Skomski, Xiao-Hui Wei, and David J. Sellmyer

Continuous/Cluster-Pinned Recording Media, Ralph Skomski, M. L. Yan, Yinfan Xu, and David J. Sellmyer

Temperature-dependent orbital-moment anisotropy in dilute magnetic oxides, Jun Zhang, Ralph Skomski, Yongfeng Lu, and David J. Sellmyer

Structure and magnetism of V-doped SnO2 thin films: effect of the substrate, Jun Zhang, Ralph Skomski, L. P. Yue, Yongfeng Lu, and David J. Sellmyer

2006

"Introduction" to Advanced Magnetic Nanostructures, David J. Sellmyer and Ralph Skomski

Magnetic Materials (Appendix to Advanced Magnetic Nanostructures [2006]), David J. Sellmyer and Ralph Skomski

"Preface" to Advanced Magnetic Nanostructures, David J. Sellmyer and Ralph Skomski

Assembly of high-anisotropy L10 FePt nanocomposite films, David J. Sellmyer, Yinfan Xu, M. L. Yan, Yucheng Sui, Jian Zhou, and Ralph Skomski

Magnetic reversal in three-dimensional exchange-spring permanent magnets, Jeffrey E. Shield, J. Zhou, S. Aich, V.K. Ravindran, Ralph Skomski, and David J. Sellmyer

Finite-temperature anisotropy of magnetic alloys, Ralph Skomski, O.N. Mryasov, J. Zhou, and David J. Sellmyer

Nanomagnetic Models, Ralph Skomski and Jian Zhou

Magnetic Aging, Ralph Skomski, Jian Zhou, Roger D. Kirby, and David J. Sellmyer

Micromagnetic energy barriers, Ralph Skomski, Jian Zhou, Roger D. Kirby, and David J. Sellmyer

Indirect exchange in dilute magnetic semiconductors, Ralph Skomski, J. Zhou, Jun Zhang, and David J. Sellmyer

Fast and Slow Magnetization Processes in Magnetic Recording Media, Jian Zhou, Ralph Skomski, Steven A. Michalski, Roger D. Kirby, and David J. Sellmyer

Structural effects on exchange in nanocluster perpendicular recording media, J. Zhou, Ralph Skomski, and David J. Sellmyer

2005

Enhanced coercivity in thermally processed (Nd,Dy)(Fe,Co,Nb,B) 5.5/ α-Fe nanoscale multilayer magnets, W. Liu, X.Z. Li, J.P. Liu, X.K. Sun, C.L. Chen, Ralph Skomski, Z.D. Zhang, and David J. Sellmyer

Phase transformations and thermodynamic properties of nanocrystalline FePt powders , J. Lyubina, O. Gutfleisch, Ralph Skomski, K.-H. Müller, and L. Schultz

Nanomagnetic Structures: Fabrication and Interactions, David J. Sellmyer, Y. C. Sui, Yinfan Xu, M. L. Yan, K. D. Sorge, and Ralph Skomski

High-Anisotropy Nanocluster Films for High-Density Perpendicular Recording, David J. Sellmyer, Minglang Yan, Yinfan Xu, and Ralph Skomski

Intra-atomic aspects of magnon-plasmon interactions, Ralph Skomski and Peter A. Dowben

Atomic and micromagnetic aspects of L10 magnetism, Ralph Skomski, Arti Kashyap, and Jian Zhou

Anisotropic exchange, Ralph Skomski, A. Kashyap, Jian Zhou, and David J. Sellmyer

Magnetic materials for finite-temperature quantum computing, Ralph Skomski, J. Zhou, A.Y. Istomin, Anthony F. Starace, and David J. Sellmyer

Relaxation in magnetic nanostructures, Ralph Skomski, J. Zhou, and David J. Sellmyer

Geometry and magnetism of L10 nanostructures, Kory D. Sorge, Ralph Skomski, Maria Daniil, Steven Michalski, L. Gao, Jian Zhou, M. Yan, Yucheng Sui, Roger D. Kirby, Sy_Hwang Liou, and David J. Sellmyer

Template-mediated assembly of FePt L10 clusters under external magnetic field, Yucheng Sui, W. Liu, L.P. Yue, X.Z. Li, J. Zhou, Ralph Skomski, and David J. Sellmyer

Magnetic properties and L10 phase formation of FePt films prepared by high current-density ion-beam irradiation and rapid thermal annealing methods, T. Yokota, M.L. Yan, Yinfan Xu, L. Gao, R. Zhang, LeighAnn Nicholl, Lu Yuan, Ralph Skomski, David J. Sellmyer, Sy_Hwang Liou, Chih-Huang Lai, Cheng-Han Yang, and Sheng-Huang Huang

Sample preparation and annealing effects on the ferromagnetism in Mn-doped ZnO, Jun Zhang, Ralph Skomski, and David J. Sellmyer

Highly coercive thin-film nanostructures, Jian Zhou, Ralph Skomski, Arti Kashyap, Kory D. Sorge, Yucheng Sui, Maria Daniil, L. Gao, M. L. Yan, Sy_Hwang Liou, Roger D. Kirby, and David J. Sellmyer

Magnetization reversal in particulate L10 nanostructures, Jian Zhou, Ralph Skomski, Kory D. Sorge, and David J. Sellmyer

Rapidly annealed exchange-coupled Sm-Co/Co multilayers, J. Zhou, Ralph Skomski, Yi Liu, Yucheng Sui, W. Liu, and David J. Sellmyer

2004

Field-controlled domain-wall resistance in magnetic nanojunctions, J. D. Burton, A. Kashyap, Mikhail Ye. Zhuravlev, Ralph Skomski, Evgeny Y. Tsymbal, Sitaram Jaswal, O.N. Mryasov, and R.W. Chantrell

Are half-metallic ferromagnets half metals? (invited), Peter A. Dowben and Ralph Skomski

Focused Ion Beam Milled CoPt Magnetic Force Microscopy Tips for High Resolution Domain Images, L. Gao, L. P. Yue, T. Yokota, Ralph Skomski, Sy-Hwang Liou, H. Takahoshi, H. Saito, and S. Ishio

Magnetism of L10 compounds with the composition MT (M = Rh, Pd, Pt, Ir and T = Mn, Fe, Co, Ni), A. Kashyap, Ralph Skomski, Ashok K. Solanki, Yinfan Xu, and David J. Sellmyer

First principles study of transition-metal substitutions in Sm–Co permanent magnets, R.F. Sabirianov, A. Kashyap, Ralph Skomski, Sitaram Jaswal, and David J. Sellmyer

Quantum entanglement of anisotropic magnetic nanodots, Ralph Skomski, Andrei Y. Istomin, Anthony F. Starace, and David J. Sellmyer

Quantum entanglement of anisotropic magnetic nanodots, Ralph Skomski, Andrei Y. Istomin, Anthony F. Starace, and David J. Sellmyer

Multidomain and incoherent effects in magnetic nanodots, Ralph Skomski, A. Kashyap, Kory D. Sorge, and David J. Sellmyer

Noncollinear spin states and competing interactions in half-metals, Ralph Skomski, Jian Zhou, Peter A. Dowben, and David J. Sellmyer

Domain-Wall Pinning at Inhomogenities of Arbitrary Cross-Sectional Geometry, Ralph Skomski, Jian Zhou, Arti Kashyap, and David J. Sellmyer

Interactions and switching behavior of anisotropic magnetic dots, Kory D. Sorge, A. Kashyap, Ralph Skomski, Lanping Yue, L. Gao, Roger D. Kirby, Sy_Hwang Liou, and David J. Sellmyer

Magnetic nanotubes produced by hydrogen reduction, Yucheng Sui, Ralph Skomski, Kory D. Sorge, and David J. Sellmyer

Nanotube magnetism, Yucheng Sui, Ralph Skomski, Kory D. Sorge, and David J. Sellmyer

Growth and magnetism of FePt:C composites in nanoscale channels, Yucheng Sui, J. Zhou, X.Z. Li, Ralph Skomski, and David J. Sellmyer

Hysteresis of Granular FePt:Ag Films With Perpendicular Anisotropy, M. L. Yan, Ralph Skomski, A. Kashyap, L. Gao, Sy-Hwang Liou, and David J. Sellmyer

Magnetization Reversal and Giant Coercivity in Sm-Co/Cu-Ti Particulate Films, Jian Zhou, Arti Kashyap, Yi Liu, Ralph Skomski, and David J. Sellmyer

2003

Finite-temperature spin polarization in half-metallic ferromagnets, Peter A. Dowben and Ralph Skomski

Exchange Interactions and Curie Temperature of Y–Co Compounds, Arti Kashyap, Ralph Skomski, Renat F. Sabiryanov, Sitaram Jaswal, and David J. Sellmyer

Spin-wave modes in magnetic nanowires, Ralph Skomski, M. Chipara, and David J. Sellmyer

Exchange through nonmagnetic insulating matrix, Ralph Skomski, A. Kashyap, Y. Quiang, and David J. Sellmyer

Finite-Temperature Anisotropy of PtCo Magnets, Ralph Skomski, Arti Kashyap, and David J. Sellmyer

Equivalence of sweep-rate and magnetic-viscosity dynamics, Ralph Skomski, Roger D. Kirby, and David J. Sellmyer

Spin structure at nanojunctions and constrictions, Ralph Skomski and David J. Sellmyer

CoPt hard magnetic nanoparticle films synthesized by high temperature chemical reduction , Yucheng Sui, L. Yue, Ralph Skomski, X.Z. Li, J. Zhou, and David J. Sellmyer

Magnetic transitions in disordered GdAl2, D. S. Williams, Paul M. Shand, Thomas M. Pekarek, Ralph Skomski, Valeri G. Petkov, and Diandra Leslie-Pelecky

Magnetic hysteresis of mechanically alloyed Sm–Co nanocrystalline powders, J. Zhou, Ralph Skomski, and David J. Sellmyer

2002

Magnetic force microscopy observations of the magnetic behavior in Co–C nanodot arrays, L. Gao, Sy_Hwang Liou, M. Zheng, Ralph Skomski, M. L. Yan, David J. Sellmyer, and N.I. Polushkin

Magnetic force microscopy observations of the magnetic behavior in Co–C nanodot arrays, L. Gao, Sy_Hwang Liou, M. Zheng, Ralph Skomski, M.L. Yan, David J. Sellmyer, and N.I. Polushkin

Exact nucleation modes in arrays of magnetic particles, Ralph Skomski

Exchange-controlled magnetic anisotropy, Ralph Skomski

The finite-temperature densities of states for half-metallic ferromagnets, Ralph Skomski and Peter A. Dowben

Structure and magnetic properties of ferromagnetic nanowires in self-assembled arrays, H. Zeng, Ralph Skomski, L. Menon, Yi Liu, S. Bandyopadhyay, and David J. Sellmyer

Permanent-Magnet Properties of Thermally Processed FePt and FePt–Fe Multilayer Films, Jian Zhou, Ralph Skomski, Xingzhong Li, Wei Tang, George C. Hadjipanayis, and David J. Sellmyer

2001

High-temperature magnetic properties of mechanically alloyed SmCo 5 and YCo5 magnets, I.A. Al-Omari, Ralph Skomski, R.A. Thomas, D. Leslie-Pelecky, and David J. Sellmyer

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 interfere 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 these 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