Mitarbeiter
 | Name: Dr. Katharina Ollefs Emailadresse: Diplom-/Masterarbeit: |
| Publikationsliste von Dr. Katharina Ollefs | |
| 2023 | |
| 30 - Formation of precipitates in off-stoichiometric Ni-Mn-Sn Heusler alloys probed through the induced Sn-moment | |
| B. Eggert, A. Çakir, D. Günzing, N. Josten, F. Scheibel, R. A. Brand, M. Farle, M. Acet, H. Wende, and K. Ollefs | |
| RSC Advances 13, 18217-18222 (2023) DOI: 10.1039/D3RA01420G | |
| 29 - Spatially-resolved dynamic sampling of different phasic magnetic resonances of nanoparticle ensembles in a magnetotactic bacterium Magnetospirillum Magnetotacticum | |
| T. Feggeler, J. Lill, D. Günzing, R. Meckenstock, D. Spoddig, M. V. Efremova, S. Wintz, M. Weigand, B. W. Zingsem, M. Farle, H. Wende, K. J. Ollefs, Hendrik Ohldag | |
| New Journal of Physic NJP-115578.R1, (2023) DOI: 10.1088/1367-2630/acc81f | |
| 28 - Evaluation protocol for revealing magnonic contrast in TR-STXM measurements | |
| B. Zingsem, Thomas Feggeler, Ralf Meckenstock, Detlef Spoddig, Taddäus Schaffers, Santa Pile, Hendrik Ohldag, Michael Farle, Heiko Wende, Andreas Ney, Katharina Ollefs | |
| AIP Advances 13, (2023) DOI: 10.1063/5.0145753 | |
| 2022 | |
| 27 - Element-specific visualization of dynamic magnetic coupling in a Co/Py bilayer microstructure | |
| T. Feggeler, Ralf Meckenstock, Detlef Spoddig, Christian Schoeppner, Benjamin Zingsem, Taddaeus Schaffers, Hendrik Ohldag, Heiko Wende, Michael Farle, Andreas Ney, Katharina Ollefs | |
| Scientific Reports 12, 18724 (2022) DOI: 10.1038/s41598-022-23273-y | |
| 2021 | |
| 26 - Spatially resolved GHz magnetization dynamics of a magnetite nano-particle chain inside a magnetotactic bacterium | |
| Thomas Feggeler, Ralf Meckenstock, Detlef Spoddig, Benjamin W. Zingsem, Hendrik Ohldag, Heiko Wende, Michael Farle, Michael Winklhofer and Katharina Ollefs | |
| Physical Review Research 3, 033036 (2021) DOI: 10.1103/PhysRevResearch.3.033036 | |
| 2020 | |
| 25 - Non-standing spin-waves in confined micrometer-sized ferromagnetic structures under uniform excitation | |
| S. Pile, T. Feggeler, T. Schaffers, R. Meckenstock, M. Buchner, D. Spoddig, B. Zingsem, V. Ney, M. Farle, H. Wende, H. Ohldag, A. Ney and K. Ollefs | |
| Applied Physics Letters 116(7), 072401-1 (2020) DOI: 10.1063/1.5139881 | |
| 2019 | |
| 24 - Extracting the Dynamic Magnetic Contrast in Time-Resolved X-Ray Transmission Microscopy | |
| T. Schaffers, T. Feggeler, S. Pile, R. Meckenstock, M. Buchner, D. Spoddig, V. Ney, M. Farle, H. Wende, S. Wintz, M. Weigand, H. Ohldag, K. Ollefs and A. Ney | |
| Nanomaterials-Basel 9(7), 940 (2019) DOI: 10.3390/nano9070940 | |
| 2018 | |
| 23 - Hysteresis Design of Magnetocaloric Materials - From Basic Mechanisms to Applications | |
| F. Scheibel, T. Gottschall, A. Taubel, M. Fries, K. P. Skokov, A. Terwey, W. Keune, K. Ollefs, H. Wende, M. Farle, M. Acet, O. Gutfleisch, M. E. Gruner | |
| Energy Technol. 6, 1397 (2018) DOI: 10.1002/ente.201800264 | |
| 2017 | |
| 22 - The combination of micro-resonators with spatially resolved ferromagnetic resonance | |
| T. Schaffers, R. Meckenstock, D. Spoddig, T. Feggeler, K. Ollefs, C. Schppner, S. Bonetti, H. Ohldag, M. Farle, and A. Ney | |
| Rev. Sci. Instrum. 88, 093703 (2017) DOI: 10.1063/1.4996780 | |
| 2015 | |
| 21 - Toward broad-band x-ray detected ferromagnetic resonance in longitudinal geometry | |
| K. Ollefs, R. Meckenstock, D. Spoddig, F. M. Rmer, Ch. Hassel, Ch. Schppner, V. Ney, M. Farle, A. Ney | |
| Journal of Applied Physics 117, 223906 (2015) DOI: 10.1063/1.4922248 | |
| 20 - Magnetic ordering in magnetic shape memory alloy Ni-Mn-In-Co | |
| K. Ollefs, Ch. Schppner, I. Titov, R. Meckenstock, F. Wilhelm, A. Rogalev, J. Liu, O. Gutfleisch, M. Farle, H. Wende, and M. Acet | |
| Physical Review B 92, 224429 (2015) | |
| 19 - Microwave soft x-ray microscopy for nanoscale magnetization dynamics in the 510 GHz frequency range | |
| Stefano Bonetti, Roopali Kukreja, Zhao Chen, Detlef Spoddig, Katharina Ollefs, Christian Schppner, Ralf Meckenstock, Andreas Ney, Jude Pinto, Richard Houanche, Josef Frisch, Joachim Sthr, Hermann A. Drr, Hendrik Ohldag | |
| Rev. Sci. Instrum. 86, 093703 (2015) DOI: 10.1063/1.4930007 | |
| 2012 | |
| 18 - Structural and magnetic analysis of epitaxial films of Gd-doped ZnO | |
| V. Ney, S. Ye, T. Kammermeier, K. Ollefs, F. Wilhelm, A. Rogalev, S. Lebgue, A. L. da Rosa, and A. Ney | |
| Phys. Rev. B 85, 235203 (2012) DOI: 10.1103/PhysRevB.85.235203 | |
| 17 - Effects of the Inhomogenous Co Doping on the Magnetoresistance of Zn1−xCoxO Epitaxial Films | |
| S. Ye, L. Klar, A. Ney, V. Ney, T. Kammermeier, K. Ollefs, F. Liu and G. Wang | |
| Journal of Nanoscience and Nanotechnology 2, 1054 (2012) DOI: 10.1166/jnn.2012.4266 | |
| 2011 | |
| 16 - Structural, chemical and magnetic properties of secondary phases in Co-doped ZnO | |
| A. Ney, A. Kovcs, V. Ney, S. Ye, K. Ollefs, T. Kammermeier, F. Wilhelm, A. Rogalev and R. E. Dunin-Borkowski | |
| New J. Phys. 13, 103001 (2011) DOI: 10.1088/1367-2630/13/10/103001 | |
| 15 - Element-Specific Magnetic Hysteresis of Individual 18 nm Fe Nanocubes | |
| F. Kronast, N. Friedenberger, K. Ollefs, S. Gliga, L. Tati-Bismaths, R. Thies, A. Ney, R. Weber, C. Hassel, F. M. Rmer, A. V. Trunova, C. Wirtz, R. Hertel, H. A. Drr and M. Farle | |
| Nano Lett. 11, 1710 (2011) DOI: 10.1021/nl200242c | |
| 2010 | |
| 14 - Co-Doped ZnO Epitaxial Films: From a Brillouin-Like Paramagnet to a Phase-Separated Superparamagnetic Ensemble | |
| V. Ney, S. Ye, K. Ollefs, T. Kammermeier, F. Wilhelm, A. Rogalev, and A. Ney | |
| J. Nanosci. Nanotechnol. 10, 5958 (2010) DOI: 10.1166/jnn.2010.2590 | |
| 13 - Magnetism of Co doped ZnO with Al codoping: Carrier-induced mechanisms versus extrinsic origins | |
| A. Ney, V. Ney, S. Ye, K. Ollefs, T. Kammermeier, T. C. Kaspar, S. A. Chambers, F. Wilhelm and A. Rogalev | |
| Phys. Rev. B 82, 041202(R) (2010) DOI: 10.1103/PhysRevB.82.041202 | |
| 12 - High-resolution x-ray lensless imaging by differential holographic encoding | |
| D. Zhu, M. Guizar- Sicairos, B. Wu, A. Scherz, Y. Acremann, T. Tyliszczak, P. Fischer, N. Friedenberger, K. Ollefs, M. Farle, J. R. Fienup, and J. Stohr | |
| Phys. Rev. Lett. 105, 043901 (2010) DOI: 10.1103/PhysRevLett.105.043901 | |
| 11 - Influence of the developing magnetic order on the transport properties of epitaxial Zn1-xCoxO films | |
| S. Ye, V. Ney, T. Kammermeier, K. Ollefs, S. Zhou, H. Schmidt, A. Ney | |
| J. Phys.: Conference Series 200, 052034 (2010) DOI: 10.1088/1742-6596/200/5/052034 | |
| 10 - Anisotropic paramagnetism of Co-doped ZnO epitaxial films | |
| A. Ney, T. Kammermeier, K. Ollefs, S. Ye, V. Ney, T. C. Kaspar, S. A. Chambers, F. Wilhelm and A. Rogalev | |
| Phys. Rev. B 81, 054420 (2010) DOI: 10.1103/PhysRevB.81.054420 | |
| 9 - Advanced spectroscopic synchrotron techniques to unravel the intrinsic properties of dilute magnetic oxides: the case of Co:ZnO | |
| A. Ney, M. Opel, T. C. Kaspar, V. Ney, S. Ye, K. Ollefs, T. Kammermeier, S. Bauer, K.-W. Nielsen, S. T. B. Goennenwein, M. H. Engelhard, S. Zhou, K. Potzger, J. Simon, W. Mader, S. M. Heald, J. C. Cezar, F. Wilhelm, A. Rogalev, R. Gross and S. A. Chambers | |
| New J. Phys. 12, 013020 (2010) DOI: 10.1088/1367-2630/12/1/013020 | |
| 8 - Tuning the magnetic properties of Zn1-xCoxO films | |
| V. Ney, S. Ye, T. Kammermeier, K. Ollefs, A. Ney, T.C. Kaspar, S.A. Chambers, F. Wilhelm and A. Rogalev | |
| J. Magn. Magn. Mater. 322, 1232 (2010) DOI: 10.1016/j.jmmm.2009.04.024 | |
| 7 - Gd-doped GaN studied with element specifity: very small polarization of Ga, paramagnetism of Gd and the formation of magnetic clusters | |
| A. Ney, T. Kammermeier, K. Ollefs, V. Ney, S. Ye, S. Dhar, K. H. Ploog, M. Rver, J. Malindretos, A. Rizzi, F. Wilhelm, A. Rogalev | |
| J. Magn. Magn. Mater. 322, 1162 (2010) DOI: 10.1016/j.jmmm.2009.06.033 | |
| 6 - Observation of the Onset of Magnetic Clustering in Superparamagnetic Zn1-xCoxO Films | |
| S. Ye, V. Ney , T. Kammermeier, K. Ollefs, A. Ney, F. Wilhelm and A. Rogalev | |
| J. Supercond. Nov. Magn. 23, 91 (2010) DOI: 10.1007/s10948-009-0566-6 | |
| 2009 | |
| 5 - Absence of ferromagnetic-transport signatures in epitaxial paramagnetic and superparamagnetic Zn0.95Co0.05O films | |
| S. Ye, V. Ney, T. Kammermeier, K. Ollefs, S. Zhou, H. Schmidt, F. Wilhelm, A. Rogalev, and A. Ney | |
| Phys. Rev. B 80, 245321 (2009) DOI: 10.1103/PhysRevB.80.245321 | |
| 4 - Element specific measurements of the structural properties and magnetism of CoxZn1-xO | |
| T. Kammermeier, V. Ney, S. Ye, K. Ollefs, T. C. Kaspar, S. A. Chambers, F.Wilhelm, A. Rogalev, and A. Ney | |
| J. Magn. Magn. Mater. 321, 699 (2009) DOI: 10.1016/j.jmmm.2008.11.028 | |
| 2008 | |
| 3 - Limitations of measuring small magnetic signals of samples deposited on a diamagnetic substrate | |
| A. Ney, T. Kammermeier, V. Ney, K. Ollefs, and S. Ye | |
| J. Magn. Magn. Mater. 320, 3341 (2008) DOI: 10.1016/j.jmmm.2008.07.008 | |
| 2 - Element specific magnetic properties of Gd:GaN: very small polarization of Ga and paramagnetism of Gd | |
| A. Ney, T. Kammermeier, V. Ney, S. Ye, K. Ollefs, E. Manuel, S. Dhar, K. H. Ploog, E. Arenholz, F. Wilhelm, and A. Rogalev | |
| Phys. Rev. B 77, 233308 (2008) DOI: 10.1103/PhysRevB.77.233308 | |
| 1 - Absence of intrinsic ferromagnetic interactions of isolated and paired Co dopant atoms in Zn1-xCoxO with high structural perfection | |
| A. Ney, K. Ollefs, S. Ye, T. Kammermeier, V. Ney, T. C. Kaspar, S. A. Chambers, F. Wilhelm, and A. Rogalev | |
| Phys. Rev. Lett. 100, 157201 (2008) DOI: 10.1103/PhysRevLett.100.157201 | |