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Dr. David J. Sellmyer, Director
Nebraska Center for Materials and Nanoscience
George Holmes University Distinquished Professor
Physics & Astronomy
George Holmes University Distinguished Professor
855 N. 16th Street,
N201A NANO
University of Nebraska
Lincoln, NE 68588-0298
office: 402 472-2407 or 7886
fax: 402 472-6148
e-mail: dsellmyer@unl.edu
Sellmyer website
Research Video
Current Research
The research in my group is broadly focused on quantum and spin phenomena in nanomagnetic structures. Newly discovered nanoscale structures with exceptional properties represent one of the most dynamic and exciting areas in science and technology. The emergence of nanoscience and nanotechnology has brought to the fore the concepts of deliberate fabrication of composite structures by either “bottom-up” or “top-down” methods. The top-down method has worked well for decades in the miniaturization process but is reaching its limits. The bottom-up method relies on the principle of self-assembly or self-organization, and has great potential for creating nanoscale systems that possess completely new properties. Future research likely will involve combined top-down and bottom-up approaches. Many new phenomena and devices are under study with these ideas including giant magnetoresistance sensors, high-density data storage and memory, spintronics, and exchange-coupled nanomagnets. Our research is focused on several of these areas.
Students and postdocs in my group learn and do research in a broad range of topics in materials, magnetism and nanoscience. Synthetic methods include sputtering, nanocluster deposition, self-assembly, electrodeposition, focused-ion-beam milling and others. Structural characterization methods include x-ray diffraction and transmission electron microscopy. Physical property measurements include SQUID, AGFM, and VSM magnetometry, electrical resistance, Hall effect, magnetoresistance, and Moessbauer effect. Our group is well known for fabrication of novel nanomagnetic structures and for strong integration of experiment with theory. Many of the topics under investigation in our group are basic science but related to nanomagnetic structures for future information technologies. These include: (i) High-anisotropy magnetic nanocluster-assembled films; (ii) Nanotube magnetism; (iii) Spin-logic nanostructures; (iv) Exchange-coupled nanocomposites; (v) Magnetic semiconductors for spintronics; and (vi) Quantum entanglement in nanodots.
Recent Publications
2012 - 2013
528. X. Wei, R. Georgescu, N. Ali, I. Morjan, T. A. George, F. Dumitrache, R. Birjega, M. Chipara, R. Skomski, and D. J. Sellmyer, "On the Synthesis and Physical Properties of Iron Doped SnO2 Nanoparticles," J. Nanosci. Nanotechnol. 12, 1–3 (2012).; doi:10.1166/jnn.2012.6784.
527. P. Kharel, Y. Huh, V. R. Shah, X. Z. Li, R. Skomski and D. J. Sellmyer, "Magnetism and Electron Transport of MnyGa (1<y<2) Nanostructures," J. Appl. Phys. (submitted Apr. 2013).
526. B. Balamurugan, B. Das, R. Skomski, W. Y. Zhang, and D.J. Sellmyer, “Nanostructured Rare-Earth-Free Magnetic Materials with Unprecedented Energy Products,” Nature Materials (submitted Apr. 2013).
525. P. Manchanda, P. K. Sahota, A. Kashyap, M. J. Lucis, J. E. Shield, A. Mubarok, J. I. Goldstein, S. Constantinides, K. Barmak, L. H. Lewis, D. J. Sellmyer, and R. Skomski, “Intrinsic Properties of Fe-Substituted L10 Magnets,” IEEE Trans. Mag. (submitted Jan. 2013).
524. W. Y. Zhang, X. Z. Li, S. Valloppilly, R. Skomski, J. E. Shield, and D. J. Sellmyer, “Magnetism of Rapidly-Quenched Rhombohedral Zr2Co11-Based Nanocomposites,” J. Phys. D: Appl. Phys. (in press).
523. W.Y. Zhang, S. Valloppilly, X.Z. Li, Y. Liu, S. Michalski, T.A. George, R. Skomski, J.E. Shield, D.J. Sellmyer, “Magnetism of Rapidly-Quenched Sm1-xZrxCo5 Nanocrystalline Materials,” IEEE Trans. Magn. (in press).
522. B. Das, B. Balasubramanian, P.K. Sahota, R. Skomski, S. Valloppilly, J.E. Shield, A. Kashyap, D.J. Sellmyer, “HfCo7-Based Rare-Earth-Free Permanent-Magnet Alloys,” IEEE Trans. Magn. (in press).
521. Y. Huh, P. Kharel, S. Valloppilly, R. Skomski, E.S. Krage, J.E. Shield, D.J. Sellmyer, “Magnetic and Structural Properties of Rapidly Quenched Tetragonal Mn3-xGa Nanostructures,” IEEE Trans. Magn. (in press).
520. P. Kharel, V.R. Shah, R. Skomski, J.E. Shield, D.J. Sellmyer, “Magnetism of MnBi-Based Nanostructures,” IEEE Trans. Magn. (in press).
519. Y. Liu and D.J. Sellmyer, “Magnetism of L10 Fe50-xCoxPt50 Films,” IEEE Trans. Magn. (in press).
518. R. Skomski, P. Manchanda, P.K. Sahota, B. Balasubramanian, A. Kashyap, D.J. Sellmyer, “Predicting the Future of Permanent-Magnet Materials,” IEEE Trans. Magn. (in press).
517. R. Skomksi, P.K. Sahota, G.C. Hadjipanayis, D.J. Sellmyer, “Finite-Temperature Micromagnetism,” IEEE Trans. Magn. (in press).
516. I.A. Al-Omari, W.Y. Zhang, Lanping Yue, R. Skomski, J.E. Shield, X.Z. Li, D.J. Sellmyer, “Hf Doping Effect on Hard Magnetism of Nanocrystalline Zr18-xHfxCo82 Ribbons,” IEEE Trans. Magn. (in press).
515. M. Chipara, L. Yue, N. Ali, Y. Xu, D.J. Sellmyer, “On FePt Nanoclusters in Polyimide,” ACS Applied Materials & Interfaces (submitted Oct. 2012).
514. Farhad Golkar, M.J. Kramer, Y. Zhang, R. Skomski, D.J. Sellmyer and J.E. Shield, “Solubility Extension and Phase Formation in Gas-Condensed Co-W Nanoclusters,” J. Nanoparticle Res. 15, 1638 (2013); DOI 10.1007/s11051-013-1638-x.
513. I.A. Al-Omari, R. Skomksi, and D.J. Sellmyer, “Magnetic Properties of Y3-2xCa2xFe5-x VxO12 Garnets,” Advances in Materials Physics and Chemistry (AMPC) (in press).
512. B. Das, B. Balamurugan, R. Skomski, X.Z. Li, P. Mukherjee, G.C. Hadjipanayis, D.J. Sellmyer, “Structure and Magnetism of Dilute Co(Zr) Nanoclusters,” J. Appl. Phys. (in press).
511. Yongsheng Yu, X.-Z. Li, T.A. George, W.D. Fei, Haibo Li, and D.J. Sellmyer, “Low Temperature Ordering and High (001) Orientation of [Fe/Pt/Cu]18 Multilayer Films,” Thin Solid Films (in press).
510. Rui Zhang, Tom A. George, Parashu Kharel, Ralph Skomski, and D. J. Sellmyer, “Susceptibility of Fe Atoms in Cu Clusters,” J. Appl. Phys. (accepted Jan. 2013).
509. P. Kharel, V.R. Shah, X.Z. Li, W.Y. Zhang, R. Skomski, J.E. Shield, and D.J. Sellmyer, “Structural and Magnetic Properties of Pr-Alloyed MnBi Nanostructures,” J. Phys. D: Appl. Phys. 46, 095003 (7 pp) (2013); doi:10.1088/0022-3727/46/9/095003.
508. Xiao-hui Wei, Rulong Zhou, B. Balamurugan, Ralph Skomski, Xiao Cheng Zeng, and D.J. Sellmyer, “Experimental and Theoretical Studies of Hydroxyl-Induced Magnetism in TiO Nanoclusters,” Nanoscale 4, 7704-7711 (2012).
507. Musa S. Shongwe, Usama A. Al-Zaabi, Faizah Al-Mjeni, Carla S. Eribal, Ekkehard Sinn, Imaddin A. Al-Omari, Hussein H. Hamdeh, Dariusz Matoga, Harry Adams, Michael J. Morris, Arnold L. Rheingold, Eckhard Bill, and David J. Sellmyer, “Accessibility and Selective Stabilization of the Principal Spin States of Iron by Pyridyl versus Phenolic Ketimines: Modulation of the 6A1 ↔ 2T2 Ground-State Transformation of the [FeN4O2]+ Chromophore,” Inorg. Chem. 51, 8241−8253 (2012); dx.doi.org/10.1021/ic300732r.
506. Wenyong Zhang, Shah R. Valloppilly, Xingzhong Li, Ralph Skomski, Jeffrey E. Shield, David J. Sellmyer, “Coercivity Enhancement in Zr2Co11-Based Nanocrystalline Materials Due to Mo Addition,” IEEE Trans. Magn. 48, 3603-3605 (2012); doi:10.1109/TMAG.2012.2198453.
505. Yongsheng Yu, T.A. George, Haibo Li, Daqian Sun, Zhenan Ren, D.J. Sellmyer, “Effects of Deposition Temperature and in-situ Annealing Time on Structure and Magnetic Properties of (001) Orientation FePt Films,” J. Magn. Magn. Matls. 328, 7-10 (2013); doi: dx.doi.org/10.1016/j.jmmm.2012.09.025.
504. 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 (2012); doi: 10.1063/1.4753950.
503. 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.
502. 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. 179-182.
501. 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.
500. P. K. Sahota, Y. Liu, R. Skomski, P. Manchanda, R. Zhang, M. Franchin, H. Fangohr, G. C. Hadjipanayis, A. Kashyap, and D. J. Sellmyer, “Ultrahard Magnetic Nanostructures,” J. Appl. Phys. 111, 07E345 (3 pages) (2012); doi:10.1063/1.3679453.
499. 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 (3 pages) (2012); doi: 10.1063/1.3679434.
498. 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 (3 pages) (2012); doi: 10.1063/1.3679085.
497. 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 (3 pages) (2012); doi: 10.1063/1.3676423.
496. R. Skomski, A. Kashyap, and D.J. Sellmyer, “A Quantum-Mechanical Relaxation Model,” J. Appl. Phys. 111, 07D507 (3 pages) (2012); doi: 10.1063/1.3679605.
495. R. Zhang, R. Skomski, X. Li, Z. Li, P. Manchanda, A. Kashyap, R.D. Kirby, S.-H. Liou, and D.J. Sellmyer, “L10 CrPt Phase Formation and Magnetic Properties,” J. Appl. Phys. 111, 07D720 (3 pages) (2012); doi: 10.1063/1.3677928.
494. 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 (3 pages) (2012); doi:10.1063/1.3676432.
493. 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 (3 pages) (2012); doi: 0.1063/1.3679099
492.B. Balasubramanian, R. Skomski, B. Das, X.Z. Li, S. Valloppilly, P. Manchanda, A. Kashyap, and D. J. Sellmyer, “Magnetism of Dilute Co(Hf) and Co(Pt) Nanoclusters,” J. Appl. Phys. 111, 07B532 (3 pages) (2012); doi: 10.1063/1.3678582.
491. B. Balasubramanian, R. Skomski, X.Z. Li, G. C. Hadjipanayis, and D. J. Sellmyer, “Magnetism of Directly Ordered Sm-Co Clusters,” J. Appl. Phys. 111, 07B527 (3 pages) (2012); doi:10.1063/1.3677668.
490. Ralph Skomski, Zhen Li, Rui Zhang, Roger D. Kirby, A. Enders, D. Schmidt, T. Hofmann, E. Schubert, and D.J. Sellmyer, “Nanomagnetic Skyrmions,” J. Appl. Phys. 111, 07E116 (3 pages) (2012); doi: 10.1063/1.3672079.
489. Ralph Skomski, B. Balamurugan, Tom A. George, Mircea Chipara, Xiao-Hui Wei, Jeff E. Shield, and D.J. Sellmyer, “Hysteresis and Relaxation in Granular Permanent Magnets,” J. Appl. Phys. 111, 07B507 (3 pages) (2012); doi: 10.1063/1.36728.
488. Farhad 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 (1-2) (2012); doi: 10.1063/1.3676425.
487. 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 (3 pages) (2012); doi: 10.1063/1.3675615.
486. 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 (1-3) (2012); doi: 10.1063/1.3672395.
485. M. Chipara, J. Hamilton, A.C. Chipara, T. George, D.M. Chipara, E.E. Ibrahim, K. Lozano, D.J. Sellmyer, "Fourier Transform Infrared Spectroscopy and Wide-Angle Ray Scattering: Investigations on Polypropylene–Vapor-Grown Carbon Nanofiber Composites," J. Appl. Polymer Science 51, 353-360 (2012), doi: 10.1002/app.35576.
2011
484. O. Akdogan, W. Li, G.C. Hadjipanayis, D.J. Sellmyer, “Synthesis of Single-Crystal Sm-Co Nanoparticles by Cluster Beam Deposition,” J. Nanoparticle Res. 13, 7005-7012 (2011); doi: 10.1007/s11051-011-0612-8.
483. R.L. Zhou, X.H. Wei, K. He, J.E. Shield, D.J. Sellmyer, X.C. Zeng, “Theoretical and Experimental Characterization of Structures of MnAu Nanoclusters in the Size Range of 1-3 nm,” ACS NANO 5, 9966-9976; doi: 10.1021/nn203739d (2011).
482. Andrei E. Surdu, Hussein H. Hamdeh, Imad A. Al-Omari, David J. Sellmyer, Alexei V. Socrovisciuc, Andrei A. Prepelita, Ezgi T. Koparan, Ekrem Yanmaz, Valery V. Ryazanov, Horst Hahn and Anatolie S. Sidorenko, “Enhancement of the Critical Current Density in FeO-Coated MgB2 Thin Films at High Magnetic Fields,” Beilstein Journal of Nanotechnology 2, 809-813 (2011); doi: 10.3762/bjnano.2.89.
481. R. Skomski, B. Balamurugan, E. Schubert, A. Enders, and D. J. Sellmyer, "Length Scales of Interactions in Magnetic, Dielectric, and Mechanical Nanocomposites," Proc. MRS 1312, mrsf10-1312-ii02-09 (12 pages) (2011); doi: 10.1557/opl.2011.109.
480. A. Kashyap, P. Manchanda, P.K. Sahota, Ralph Skomski, J.E. Shield, D. J. Sellmyer, “Anisotropy of W in Fe and Co,” IEEE Trans. Mag. 47, 3336-3339 (2011); doi: 10.1109/TMAG.2011.2157317.
479. Y. Liu, T.A. George, Ralph Skomski and D.J. Sellmyer, “Aligned and Exchange-Coupled FePt-Based Films,” Appl. Phys. Lett. 99, 172504 (3 pages) (2011); doi:10.1063/1.3656038.
478. M. Chipara, R. Skomski, R. Kirby, D.J. Sellmyer, "Ferromagnetic Resonance on Ni Nanowire Arrays," J. Matls. Res. 26, 2169-2174 (2011); doi: 10.1557/jmr.2011.146.
477. P. Kharel and D.J. Sellmyer, “Anomalous Hall Effect and Electron Transport in Ferromagnetic MnBi Films,” J. Phys. Cond. Matt. 23, 426001(1-5) (2011); doi: 10.1088/0953-8984/23/42/426001.
475. B. Balasubramanian, D.J. Sellmyer, S. Ducharme, S. Valloppilly, K. Kraemer, “Cluster Synthesis of Monodisperse Rutile-TiO2 Nanoparticles and Dielectric TiO2-Vinylidene Fluoride Oligomer Nanocomposites,” Nanotechnology 22, 405605 (1-8) (2011); doi: 10.1088/0957-4484/22/40/405605.
474. 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); doi: 10.1063/1.3562254.
473. 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); doi: 10.1063/1.3559505.472. X.Z. Li, P. Kharel, V.R. Shah, D.J. Sellmyer, “Synthesis and Characterization of Highly Textured Pt-Bi Thin Films,” Philosophical Magazine 91, 3406-3415 (2011); doi: 10.1080/14786435.2011.580289.
471. T. Mukherjee, S. Michalski, R. Skomski, D.J. Sellmyer, C. Binek, et al., 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); doi: 10.1103/PhysRevB.83.214413.470. D. Le Roy, W. Yang, X. Yin, R. Y. Lai, S.-H. Liou, and D. J. Sellmyer, "High-Sensitivity Detector for Molecular Sensing Using Magnetic Particles," J. Appl. Phys. 109, 07E532 (1-3) (2011); doi: 10.1063/1.3564951.
469. B. Balasubramanian, 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); doi: 10.1063/1.3549602.
468. 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); doi: 10.1063/1.3559502.
467. 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); doi: 10.1063/1.3556953.
466. 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); doi: 10.1063/1.3537952.
465. 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); doi: 10.1063/1.3556766.
464. 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); doi: 10.1063/1.3562256.
463. P. Kharel, R. Skomski, P. Lukashev, R. Sabirianov, and D.J. Sellmyer, "Spin Correlations and Kondo Effect in a Strong Ferromagnet," Physical Review B 84, 014431 (1-5) (2011); doi: 10.1103/PhysRevB.84.014431.
462. X.Z. Li, Y.S. Yu, T. George, and D.J. Sellmyer, “Structural Studies of Mono-atomic Layer-deposited (FePt)1-xCux Thin Films and FePt Thin Films with Pt Top-layer Deposition,” Microsc. Microanal. 16 (Suppl 2), 1772-1773 (2010) doi: 10.1017/S1431927610053717.
461. B. Balamurugan, R. Skomski, X. Li, S. Valloppilly, J. Shield, G.C. Hadjipanayis, D.J. Sellmyer, “Cluster Synthesis and Direct Ordering of Rare-Earth Transition-Metal Nanomagnets,” Nano Lett. 11, 1747-1752 (2011); doi: 10.1021/nl200311w.