Faculty - Skomski

Dr. Ralph Skomski e-mail: Dr. Skomski NCMN Homepage

Dr. Ralph Skomski, Research Associate Professor
Physics & Astronomy
University of Nebraska - Lincoln
089 T. Jorgensen Hall
Lincoln, Nebraska 68588-0299
office: (402) 472-0180
email: rskomski2@unl.edu or rskomski@nebrr.com
Sellmyer Group Lab

Current Research

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.

Recent Publications

  1. R. Skomski, A. Kashyap, and A. Enders, "Is the magnetic anisotropy proportional to the orbital moment?", J. Appl. Phys. 109, 07E143-1-3 (2011).
  2. R. Skomski, "Are there superspin glasses?", J. Appl. Phys. 109, 07E149-1-3 (2011).
  3. M. A. Peck, Y. Huh, R. Skomski, R. Zhang, P. Kharel, M. D. Allison, D. J. Sellmyer, and M. A. Langell, "Magnetic properties of NiO and (Ni, Zn)O nanoclusters", J. Appl. Phys. 109, 07B518-1-3 (2011).
  4. P. K. Sahota, R. Skomski, A. Enders, D. J. Sellmyer, and A. Kashyap, "Anisotropy of zigzag chains of palladium", J. Appl. Phys. 109, 07E322-1-3 (2011).
  5. X. Wei, D. Le Roy, R. Skomski, X. Z. Li, Z. Sun, J. E. Shield, M. J. Kramer, and D. J. Sellmyer, "Structure and magnetism of MnAu nanoclusters", J. Appl. Phys. 109, 07B523-1-3 (2011).
  6. A. Kashyap, R. Skomski, P. Manchanda, J. E. Shield, and D. J. Sellmyer, "Layered transition-metal permanent-magnet structures", J. Appl. Phys. 109, 07A714-1-3 (2011).
  7. S. Michalski, R. Skomski, T. Mukherjee, X.-Zh. Li, Ch. Binek, and D. J. Sellmyer, "Magnetic entropy changes in nanogranular Fe:Ni61Cu39", J. Appl. Phys. 109, 07A936-1-3 (2011).
  8. B. Balamurugan, R. Skomski, X. Z. Li, V. R. Shah, G. C. Hadjipanayis, J. E. Shield, and D. J. Sellmyer, "Magnetism of cluster-deposited Y–Co nanoparticles", J. Appl. Phys. 109, 07A707-1-3 (2011).
  9. V. Sharma, P. Manchanda, R. Skomski, D. J. Sellmyer, and A. Kashyap, "Anisotropy of heavy transition metal dopants in Co", J. Appl. Phys. 109, 07A727-1-3 (2011).
  10. P. Kharel, R. Skomski, and D. J. Sellmyer, "Spin correlations and electron transport in MnBi:Au films", J. Appl. Phys. 109, 07B709-1-3 (2011).
  11. P. Manchanda, P. K. Sahota, R. Skomski, P. S. Anil Kumar, and A. Kashyap, "First-principle description of magnonic PdnFem multilayers", J. Appl. Phys. 109, 07C110-1-3 (2011).
  12. Zh. Li, R. Skomski, S.-H. Liou, S. Michalski, M. Chipara, and R. D. Kirby, "Magnetization precession and domain-wall structure in cobalt-ruthenium-cobalt trilayers", J. Appl. Phys. 109, 07C113-1-3 (2011).
  13. B. Balasubramanian, R. Skomski, X.-Zh. Li, Sh. R. Valloppilly, J. E. Shield, G. C. Hadjipanayis, and D. J. Sellmyer, "Cluster Synthesis and Direct Ordering of Rare-Earth Transition-Metal Nanomagnets", Nano Lett. 11, 1747-1752 (2011).
  14. P. Kharel, R. Skomski, P. Lukashev, R. Sabirianov, and D. J. Sellmyer, "Spin correlations and Kondo effect in a strong ferromagnet", Phys. Rev. B 84, 014431-1-5 (2011).
  15. T. Hofmann, D. Schmidt, A. Boosalis, P. Kühne, R. Skomski, C. M. Herzinger, J. A. Woollam, M. Schubert, and E. Schubert, "THz dielectric anisotropy of metal slanted columnar thin films", Appl. Phys. Lett. 99, 081903-1-3 (2011).
  16. T. Mukherjee, S. Michalski, R. Skomski, D. J. Sellmyer, and Ch. Binek, "Overcoming the spin-multiplicity limit of entropy by means of lattice degrees of freedom: A minimal model", Phys. Rev. B 83, 214413-1-5 (2011).
  17. R. Skomski, B. Balamurugan, E. Schubert, A. Enders and D. J. Sellmyer, "Length scales of interactions in magnetic, dielectric, and mechanical nanocomposites", MRS Proceedings 1312, mrsf10-1312-ii02-09 (12 pages).
  18. Y. Liu, T. A. George, Ralph Skomski, and D. J. Sellmyer, "Aligned and exchange-coupled FePt-based films", Appl. Phys. Lett. 99, 172504-1-3 (2011).
  19. P. Manchanda, R. Skomski, A. K. Solanki, P. S. A. Kumar, A. Kashyap, "Magnetoelectric Effect in L10-CoPd Thin Films", IEEE Trans. Magn. 47 (10), 4391-4393 (2011).
  20. A. Kashyap, P. Manchanda, P. K. Sahota, R. Skomski, J. E. Shield, D. J. Sellmyer, "Anisotropy of W in Fe and Co", IEEE Trans. Magn. 47 (10), 3336-3339 (2011).
  21. R. Skomski, B. Balamurugan, T. A. George, M. Chipara, X.-H. Wei, J. E. Shield, and D. J. Sellmyer, "Hysteresis and Relaxation in Granular Permanent Magnets", J. Appl. Phys. 111, 07B507-1-3 (2012)
  22. R. Skomski, Zh. Li, R. Zhang, R. D. Kirby, A. Enders, D. Schmidt, T. Hofmann, E. Schubert, and D. J. Sellmyer, "Nanomagnetic Skyrmions", J. Appl. Phys. 111, 07E116-1-1-3 (2012).
  23. R. Skomski, "Berry Phase from A Randomly Fluctuating Magnetic Field", J. Appl. Phys. 111, 07E102-1-3 (2012).
  24. R. Skomski, A. Kashyap, and D. J. Sellmyer, "A Quantum-Mechanical Relaxation Model", J. Appl. Phys. 111, 07D507-1-3 (2012).
  25. P. K. Sahota, Y. Liu, R. Skomski, P. Manchanda, R. Zhang, H. Fangohr, M. Franchin, G. C. Hadjipanayis, A. Kashyap, and D. J. Sellmyer, "Ultrahard Magnetic Nanostructures", J. Appl. Phys. 111, 07E345-1-3 (2012).
  26. P. Manchanda, R. Skomski, P. K. Sahota, M. Franchin, H. Fangohr and A. Kashyap, "Multiscale Micromagnetism of Co-Pd Multilayers", J. Appl. Phys. 111, 07C724-1-3 (2012).
  27. B. Balamurugan, R. Skomski, B. Das, X. Z. Li, V. R. Shah, P. Manchanda, A. Kashyap, and D. J. Sellmyer, "Magnetism of dilute Co(Hf) and Co(Pt) nanoclusters", J. Appl. Phys. 111, 07B532-1-3 (2012).
  28. B. Balamurugan, R. Skomski, X. Z. Li, G. C. Hadjipanayis, and D. J. Sellmyer, "Magnetism of directly ordered Sm-Co clusters", J. Appl. Phys. 111, 07B527-1-3 (2012).
  29. F. Golkar, M. J. Kramer, Y. Zhang, R. W. McCallum, R. Skomski, D. J. Sellmyer, and J. E. Shield, "Structure and magnetic properties of Co-W clusters produced by inert gas condensation", J. Appl. Phys. 111, 07B524-1-3 (2012).
  30. B. Das, B. Balamurugan, W. Y. Zhang, R. Skomski, E. S. Krage, S. R. Valloppilly, J. E. Shield, and D. J. Sellmyer, "Magnetism of Less Common Cobalt-Rich Alloys", Proc. REPM’12, Nagasaki 2012, p. 427-430.
  31. P. Kharel, X. Z. Li, V. R. Shah, N. Al-Aqtash, K. Tarawneh, R. F. Sabirianov, R. Skomski, and D. J. Sellmyer, "Structural, magnetic, and electron transport properties of MnBi:Fe thin films", J. Appl. Phys. 111, 07E326-1-3 (2012).
  32. P. Kharel, Y. Huh, V. R. Shah, X. Z. Li, N. Al-Aqtash, K. Tarawneh, E. S. Krage, R. F. Sabirianov, R. Skomski, and D. J. Sellmyer, "Structural and magnetic properties of Mn2+δTiSn", J. Appl. Phys. 111, 07B101 (2012).
  33. R. Zhang, R. Skomski, X.-Zh. Li, Zh. Li, P. Manchanda, A. Kashyap, R. D. Kirby, S.-H. Liou, D. J. Sellmyer, "L10 CrPt phase formation and magnetic properties", J. Appl. Phys. 111, 07D7201-3 (2012).
  34. P. Manchanda,  R. Skomski,  J. E. Shield,  S. Constantinides,  and A. Kashyap, "Intrinsic Magnetic Properties of L10-Based Mn-Al and Fe-Co-Pt Alloys", Proc. REPM’12, Nagasaki 2012, p. 115-118.
  35. S. Michalski, R. Skomski, X.-Zh. Li, D. Le Roy, T. Mukherjee, Ch. Binek, and D. J. Sellmyer, "Isothermal entropy changes in nanocomposite Co:Ni67Cu33", J. Appl. Phys. 111, 07A930-1-3 (2012).
  36. T. Mukherjee, R. Skomski, S. Michalski, D. J. Sellmyer, and Ch. Binek, "Spin and elastic contributions to isothermal entropy change", J. Appl. Phys. 111, 07A931-1-3 (2012).
  37. D. Le Roy, S. Valloppilly, R. Skomski, S.-H. Liou, and D. J. Sellmyer, "Magnetism and structure of anatase (Ti1−xVx)O2 films", J. Appl. Phys. 111, 07C118-1-3 (2012).
  38. Y. Liu, T. A. George, R. Skomski, and D. J. Sellmyer, "Aligned and exchange-coupled L10 (Fe,Co)Pt-based magnetic films", J. Appl. Phys. 111, 07B537-1-3 (2012).
  39. R. Skomski, P. K. Sahota, B. Balamurugan, J. E. Shield, A. Kashyap, and D. J. Sellmyer, "Geometrical Aspects of Hard-Soft Exchange Coupling", Proc. REPM’12, Nagasaki 2012, p. 155-158.
  40. O. Akdogan, W. Li, G. C. Hadjipanayis, R. Skomski, and D. J. Sellmyer,  "One-step fabrication of L10 FePt nanocubes and rods by cluster beam deposition", J. Appl. Phys. 111, 07B535-1-3 (2012).
  41. L. H. Lewis, K. Barmak, J. G. Goldstein, F. Pinkerton, and R. Skomski, "Towards Stabilization of L10-type FeNi Compounds for Permanent Magnet Applications", Proc. REPM’12, Nagasaki 2012, p. 102-105.
  42. D. J. Sellmyer, B. Balamurugan, Y. Liu, and R. Skomski, "Assembly and Alignment of Nano-objects for Advanced Magnetic Materials", Proc. REPM’12, Nagasaki 2012, p. 180-182.
  43. B. Balamurugan, B. Das, V. R. Shah, R. Skomski, X. Z. Li, and D. J. Sellmyer, "Assembly of uniaxially aligned rare-earth-free nanomagnets", Appl. Phys. Lett. 101, 122407-1-5 (2012).
  44. W.-Y. Zhang, Sh. R. Valloppilly, X.-Zh. Li, R. Skomski, J. E. Shield, and D. J. Sellmyer, "Coercivity Enhancement in Zr2Co11-Based Nanocrystalline Materials Due to Mo Addition", IEEE Trans. Magn. 48 (11), 3603-3605 (2012).
  45. B.  Balamurugan, D. J. Sellmyer, G. C. Hadjipanayis, and R. Skomski, "Prospects for nanoparticle-based permanent magnets", Scripta Materialia 67, 542-547 (2012).
  46. V. Sharma, P. Manchanda, P. K. Sahota, R. Skomski, and A. Kashyap, "Interatomic exchange in Mn-doped III-V semiconductors", J. Magn. Magn. Mater. 324, 786-791 (2012).
  47. X.-H. Wei, R.-L. Zhou, B. Balamurugan, R. Skomski, X. C. Zeng, D. J. Sellmyer, "Experimental and theoretical studies of hydroxyl-induced magnetism in TiO nanoclusters", NANOSCALE 4, 7704-7711 (2012).
  48. B. Yang, Zh.-G. Xiao, Y.-B. Yuan, T. V. Jayaraman, J. E. Shield, R. Skomski, and J.-S. Huang, "Room-temperature organic ferromagnetism in the crystalline poly(3-hexylthiophene): Phenyl-C61-butyric acid methyl ester blend film", Polymer 54, 490-494 (2013).
  49. I. A. Al-Omari, R. Skomski, D. J. Sellmyer, "Magnetic Properties of Y3−2xCa2xFe5-xVxO12 Garnets", Advances in Materials Physics and Chemistry 2, 116-120 (2012).
  50. P. V. Lukashev, J.-Hy. Kim, S. Yang, J.-S. Kim, X. Chen, G. Rojas, J. Honolka, R. Skomski, A. Enders, and R. F. Sabirianov, "Magnetic phases of cobalt atomic clusters on tungsten", J. Phys.: Condens. Matter 25, 036003-1-4 (2013).

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, PRL 102, 067207 (2009).

R. Skomski, Simple Models of Magnetism, Oxford University Press (2008).

R. Skomski, J. Zhang, V. Sessi, J. Honolka, K. Kern, and A. Enders, “Substrate-controlled Growth and Magnetism of Nanosize Fe Clusters on Pt”, J. Appl. Phys. 103, 07D519 (2008).

R. Skomski, “Phase Formation in L10 Magnets”, J. Appl. Phys. 101, 09N517 (2007).

J. Zhang, R. Skomski, Y. F. Lu, and D. J. Sellmyer, “Temperature-dependent Orbital-moment Anisotropy in Dilute Magnetic Oxides”, Phys. Rev. B 75, 214417 (2007).

Advanced Magnetic Nanostructures, eds. D. J. Sellmyer and R. Skomski, Springer (2006).

D. J. Sellmyer, M. L. Yan, Y. F. Xu, and R. Skomski, “High-Anisotropy Nanocluster Films for High-Density Perpendicular Recording,” IEEE Trans. Mag. 41, 560-565 (2005).

Y. C. Sui, R. Skomski, K. D. Sorge, and D. J. Sellmyer, “Nanotube Magnetism”, Appl. Phys. Lett. 84, 1525-1527 (2004).

R. Skomski, “Nanomagnetics”, Topical Review, J. Phys.: Condens. Matter 15, R841-R896R (2003).

R. Skomski and P. A. Dowben, “The Finite-Temperature Densities of States for Half-Metallic Ferromagnets”, Europhys. Lett. 58, 544-548 (2002).

R. Skomski and J. M. D. Coey, “Permanent Magnetism”, Institut of Physics, Bristol, 1999.