Header logo is de


2020


Biocompatible magnetic micro‐ and nanodevices: Fabrication of FePt nanopropellers and cell transfection
Biocompatible magnetic micro‐ and nanodevices: Fabrication of FePt nanopropellers and cell transfection

Kadiri, V. M., Bussi, C., Holle, A. W., Son, K., Kwon, H., Schütz, G., Gutierrez, M. G., Fischer, P.

Adv. Mat., 32(2001114), May 2020 (article)

Abstract
The application of nanoparticles for drug or gene delivery promises benefits in the form of single‐cell‐specific therapeutic and diagnostic capabilities. Many methods of cell transfection rely on unspecific means to increase the transport of genetic material into cells. Targeted transport is in principle possible with magnetically propelled micromotors, which allow responsive nanoscale actuation and delivery. However, many commonly used magnetic materials (e.g., Ni and Co) are not biocompatible, possess weak magnetic remanence (Fe3O4), or cannot be implemented in nanofabrication schemes (NdFeB). Here, it is demonstrated that co‐depositing iron (Fe) and platinum (Pt) followed by one single annealing step, without the need for solution processing, yields ferromagnetic FePt nanomotors that are noncytotoxic, biocompatible, and possess a remanence and magnetization that rival those of permanent NdFeB micromagnets. Active cell targeting and magnetic transfection of lung carcinoma cells are demonstrated using gradient‐free rotating millitesla fields to drive the FePt nanopropellers. The carcinoma cells express enhanced green fluorescent protein after internalization and cell viability is unaffected by the presence of the FePt nanopropellers. The results establish FePt, prepared in the L10 phase, as a promising magnetic material for biomedical applications with superior magnetic performance, especially for micro‐ and nanodevices.

pf mms

link (url) DOI [BibTex]


no image
Effect of the soft layer thickness of magnetization reversal process of exchange-spring nanomagnet patterns

Son, K., Schütz, G., Goering, E.

{Current Applied Physics}, 20(4):477-483, Elsevier B.V., Amsterdam, 2020 (article)

mms

DOI [BibTex]


{Creating zero-field skyrmions in exchange-biased multilayers through X-ray illumination}
Creating zero-field skyrmions in exchange-biased multilayers through X-ray illumination

Guang, Y., Bykova, I., Liu, Y., Yu, G., Goering, E., Weigand, M., Gräfe, J., Kim, S. K., Zhang, J., Zhang, H., Yan, Z., Wan, C., Feng, J., Wang, X., Guo, C., Wei, H., Peng, Y., Tserkovnyak, Y., Han, X., Schütz, G.

{Nature Communications}, 11, Nature Publishing Group, London, 2020 (article)

Abstract
Skyrmions, magnetic textures with topological stability, hold promises for high-density and energy-efficient information storage devices owing to their small size and low driving-current density. Precise creation of a single nanoscale skyrmion is a prerequisite to further understand the skyrmion physics and tailor skyrmion-based applications. Here, we demonstrate the creation of individual skyrmions at zero-field in an exchange-biased magnetic multilayer with exposure to soft X-rays. In particular, a single skyrmion with 100-nm size can be created at the desired position using a focused X-ray spot of sub-50-nm size. This single skyrmion creation is driven by the X-ray-induced modification of the antiferromagnetic order and the corresponding exchange bias. Furthermore, artificial skyrmion lattices with various arrangements can be patterned using X-ray. These results demonstrate the potential of accurate optical control of single skyrmion at sub-100 nm scale. We envision that X-ray could serve as a versatile tool for local manipulation of magnetic orders.

mms

DOI [BibTex]

DOI [BibTex]


{Tuning the magnetic properties of permalloy-based magnetoplasmonic crystals for sensor applications}
Tuning the magnetic properties of permalloy-based magnetoplasmonic crystals for sensor applications

Murzin, D. V., Belyaev, V. K., Groß, F., Gräfe, J., Rivas, M., Rodionova, V. V.

{Japanese Journal of Applied Physics}, 59(SE), IOP Publishing Ltd, Bristol, England, 2020 (article)

Abstract
Miniature magnetic sensors based on magnetoplasmonic crystals (MPlCs) exhibit high sensitivity and high spatial resolution, which can be obtained by the excitation of surface plasmon polaritons. A field dependence of surface plasmon polaritons' enhanced magneto-optical response strongly correlates with magnetic properties of MPlCs that can be tuned by changing spatial parameters, such as the period and height of diffraction gratings and thicknesses of functional layers. This work compares the magnetic properties of MPlCs based on Ni80Fe20 (permalloy) obtained from local (longitudinal magneto-optical Kerr effect) and bulk (vibrating-sample magnetometry) measurements and demonstrates an ability to control sensors' performance through changing the magnetic properties of the MPlCs. The influence of the substrate's geometry (planar or sinusoidal and trapezoidal diffraction grating profiles) and the thickness of the surface layer is examined.

mms

DOI [BibTex]

DOI [BibTex]


no image
Specific isotope-responsive breathing transition in flexible metal-organic frameworks

Kim, J. Y., Park, J., Ha, J., Jung, M., Wallacher, D., Franz, A., Balderas-Xicohténcatl, R., Hirscher, M., Kang, S. G., Park, J. T., Oh, I. H., Moon, H. R., Oh, H.

Journal of the American Chemical Society, 142(31):13278-13282, American Chemical Society, Washington, DC, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Magnetische Röntgenmikroskopie zur Untersuchung des lokalen Stromtransports in Supraleitern

Simmendinger, J.

Universität Stuttgart, Stuttgart (und Verlag Dr. Hut, München), 2020 (phdthesis)

mms

[BibTex]

[BibTex]


no image
Magnetic state control via field-angle-selective switching in asymmetric rings

Schönke, D., Reeve, R. M., Stoll, H., Kläui, M.

Physical Review Applied, 14(3), American Physical Society, College Park, Md. [u.a.], 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Element-resolved study of the evolution of magnetic response in FexN compounds

Chen, Y., Gölden, D., Dirba, I., Huang, M., Gutfleisch, O., Nagel, P., Merz, M., Schuppler, S., Schütz, G., Alff, L., Goering, E.

{Journal of Magnetism and Magnetic Materials}, 498, NH, Elsevier, Amsterdam, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
The role of temperature and drive current in skyrmion dynamics

Litzius, K., Leliaert, J., Bassirian, P., Rodrigues, D., Kromin, S., Lemesh, I., Zazvorka, J., Lee, K., Mulkers, J., Kerber, N., Heinze, D., Keil, N., Reeve, R. M., Weigand, M., Van Waeyenberge, B., Schütz, G., Everschor-Sitte, K., Beach, G. S. D., Kläui, M.

{Nature Electronics}, 3(1):30-36, Springer Nature, London, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Magnetic flux penetration into micron-sized superconductor/ferromagnet bilayers

Simmendinger, J., Weigand, M., Schütz, G., Albrecht, J.

{Superconductor Science and Technology}, 33(2), IOP Pub., Bristol, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Interaction of hydrogen isotopes with flexible metal-organic frameworks

Bondorf, L.

Universität Stuttgart, Stuttgart, 2020 (mastersthesis)

mms

[BibTex]

[BibTex]


no image
Demonstration of k-vector selective microscopy for nanoscale mapping of higher order spin wave modes

Träger, N., Gruszecki, P., Lisiecki, F., Groß, F., Förster, J., Weigand, M., Glowinski, H., Kuswik, P., Dubowik, J., Krawczyk, M., Gräfe, J.

Nanoscale, 12(33):17238-17244, Royal Society of Chemistry, Cambridge, UK, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Direct observation of spin-wave focusing by a Fresnel lens

Gräfe, J., Gruszecki, P., Zelent, M., Decker, M., Keskinbora, K., Noske, M., Gawronski, P., Stoll, H., Weigand, M., Krawczyk, M., Back, C. H., Goering, E. J., Schütz, G.

Physical Review B, 102(2), American Physical Society, Woodbury, NY, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Bandgap-adjustment and enhanced surface photovoltage in Y-substituted LaTaIVO2N

Bubeck, C., Widenmeyer, M., De Denko, A. T., Richter, G., Coduri, M., Salas-Colera, E., Goering, E., Zhang, H., Yoon, S., Osterloh, F. E., Weidenkaff, A.

Journal of Materials Chemistry A, 8(23):11837-11848, Royal Society of Chemistry, Cambridge, UK, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Single shot acquisition of spatially resolved spin wave dispersion relations using X-ray microscopy

Träger, N., Groß, F., Förster, J., Baumgaertl, K., Stoll, H., Weigand, M., Schütz, G., Grundler, D., Gräfe, J.

Scientific Reports, 10, Nature Publishing Group, London, UK, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Fabrication and temperature-dependent magnetic properties of large-area L10-FePt/Co exchange-spring magnet nanopatterns

Son, K., Schütz, G.

{Physica E: Low-Dimensional Systems And Nanostructures}, 115, North-Holland, Amsterdam, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Research trend of metal-organic frameworks for magnetic refrigeration materials application

Kim, S., Son, K., Oh, H.

Korean Journal of Materials Research, 30(3):136-141, Materials Society of Korea, Seoul, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


Magnetic Anisotropy in Thin Layers of (Mn,Zn)Fe2O4 on SrTiO3 (001)
Magnetic Anisotropy in Thin Layers of (Mn,Zn)Fe2O4 on SrTiO3 (001)

Denecke, R., Welke, M., Huth, P., Gräfe, J., Brachwitz, K., Lorenz, M., Grundmann, M., Ziese, M., Esquinazi, P. D., Goering, E., Schütz, G., Schindler, K., Chassé, A.

Physica Status Solidi (b), 257(7):1900627, 2020 (article)

Abstract
Herein, a ferrimagnetic manganese zinc ferrite (Mn0.5Zn0.5Fe2O4) film with a thickness of 200 nm is prepared without a buffer layer on strontium titanate (001) (SrTiO3) using pulsed laser deposition. Its magnetic properties are investigated using superconducting quantum interference device (SQUID), X-ray absorption spectroscopy with subsequent X-ray magnetic circular dichroism (XMCD) and magneto-optic Kerr effect (MOKE). Hysteresis loops derived from SQUID exhibits bulk-like properties. This can further be confirmed by bulk-like XMCD spectra. In remanent magnetization, an in-plane magnetization with basically no out-of-plane component is found. The magnetic moments derived by the sum rule formalism from the XMCD data are in good agreement to the magnetization observed by SQUID and MOKE. XMCD as well as MOKE reveal an in-plane angular fourfold magnetic anisotropy with the easy direction along [110] for (Mn0.5Zn0.5)Fe2O4 on SrTiO3. The element-specific magnetic moments from XMCD show a stronger contribution of Fe to the anisotropy than of Mn and distinct contributions of the orbital moments.

mms

link (url) DOI [BibTex]

link (url) DOI [BibTex]


no image
In situ x-ray diffraction and spectro-microscopic study of ALD protected copper films

Dogan, G., Sanli, U. T., Hahn, K., Müller, L., Gruhn, H., Silber, C., Schütz, G., Grévent, C., Keskinbora, K.

ACS Applied Materials and Interfaces, 12(29):33377-33385, American Chemical Society, Washington, DC, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
How to functionalise metal-organic frameworks to enable guest nanocluster embedment

King, J., Zhang, L., Doszczeczko, S., Sambalova, O., Luo, H., Rohman, F., Phillips, O., Borgschulte, A., Hirscher, M., Addicoat, M., Szilágyi, P. A.

{Journal of Materials Chemistry A}, 8(9):4889-4897, Royal Society of Chemistry, Cambridge, UK, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Magnetic and microstructural properties of anisotropic MnBi magnets compacted by spark plasma sintering

Chen, Y., Gregori, G., Rheingans, B., Huang, W., Kronmüller, H., Schütz, G., Goering, E.

{Journal of Alloys and Compounds}, 830, Elsevier B.V., Lausanne, Switzerland, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Biocompatible magnetic micro- and nanodevices: Fabrication of FePt nanopropellers and cell transfection

Kadiri, V. M., Bussi, C., Holle, A. W., Son, K., Kwon, H., Schütz, G., Gutierrez, M. G., Fischer, P.

Advanced Materials, 32(25), Wiley-VCH, Weinheim, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Metal organic frameworks as tunable linear magnets

Son, K., Kim, R. K., Kim, S., Schütz, G., Choi, K. M., Oh, H.

Physica Status Solidi A, 217(12), Wiley-VCH, Weinheim, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Observation of compact ferrimagnetic skyrmions in DyCo3 fim

Chen, K., Lott, D., Philippi-Kobs, A., Weigand, M., Luo, C., Radu, F.

Nanoscale, 12(35):18137-18143, Royal Society of Chemistry, Cambridge, UK, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Generation and characterization of focused helical x-ray beams

Loetgering, L., Baluktsian, M., Keskinbora, K., Horstmeyer, R., Wilhein, T., Schütz, G., Eikema, K. S. E., Witte, S.

Science Advances, 6(7), American Association for the Advancement of Science, 2020 (article)

mms

Generation and characterization of focused helical x-ray beams link (url) DOI [BibTex]

Generation and characterization of focused helical x-ray beams link (url) DOI [BibTex]


no image
Materials for hydrogen-based energy storage - past, recent progress and future outlook

Hirscher, M., Yartys, V. A., Baricco, M., Bellosta von Colbe, J., Blanchard, D., Bowman Jr., R. C., Broom, D. P., Buckley, C. E., Chang, F., Chen, P., Cho, Y. W., Crivello, J., Cuevas, F., David, W. I. F., de Jongh, P. E., Denys, R. V., Dornheim, M., Felderhoff, M., Filinchuk, Y., Froudakis, G. E., Grant, D. M., Gray, E. M., Hauback, B. C., He, T., Humphries, T. D., Jensen, T. R., Kim, S., Kojima, Y., Latroche, M., Li, H., Lotostskyy, M. V., Makepeace, J. W., M\oller, K. T., Naheed, L., Ngene, P., Noréus, D., Nyg\aard, M. M., Orimo, S., Paskevicius, M., Pasquini, L., Ravnsbaek, D. B., Sofianos, M. V., Udovic, T. J., Vegge, T., Walker, G. S., Webb, C. J., Weidenthaler, C., Zlotea, C.

{Journal of Alloys and Compounds}, 827, Elsevier B.V., Lausanne, Switzerland, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


{Thermal nucleation and high-resolution imaging of submicrometer magnetic bubbles in thin thulium iron garnet films with perpendicular anisotropy}
Thermal nucleation and high-resolution imaging of submicrometer magnetic bubbles in thin thulium iron garnet films with perpendicular anisotropy

Büttner, F., Mawass, M. A., Bauer, J., Rosenberg, E., Caretta, L., Avci, C. O., Gräfe, J., Finizio, S., Vaz, C. A. F., Novakovic, N., Weigand, M., Litzius, K., Förster, J., Träger, N., Groß, F., Suzuki, D., Huang, M., Bartell, J., Kronast, F., Raabe, J., Schütz, G., Ross, C. A., Beach, G. S. D.

{Physical Review Materials}, 4(1), American Physical Society, College Park, MD, 2020 (article)

Abstract
Ferrimagnetic iron garnets are promising materials for spintronics applications, characterized by ultralow damping and zero current shunting. It has recently been found that few nm-thick garnet films interfaced with a heavy metal can also exhibit sizable interfacial spin-orbit interactions, leading to the emergence, and efficient electrical control, of one-dimensional chiral domain walls. Two-dimensional bubbles, by contrast, have so far only been confirmed in micrometer-thick films. Here, we show by high resolution scanning transmission x-ray microscopy and photoemission electron microscopy that submicrometer bubbles can be nucleated and stabilized in ∼25-nm-thick thulium iron garnet films via short heat pulses generated by electric current in an adjacent Pt strip, or by ultrafast laser illumination. We also find that quasistatic processes do not lead to the formation of a bubble state, suggesting that the thermodynamic path to reaching that state requires transient dynamics. X-ray imaging reveals that the bubbles have Bloch-type walls with random chirality and topology, indicating negligible chiral interactions at the garnet film thickness studied here. The robustness of thermal nucleation and the feasibility demonstrated here to image garnet-based devices by x-rays both in transmission geometry and with sensitivity to the domain wall chirality are critical steps to enabling the study of small spin textures and dynamics in perpendicularly magnetized thin-film garnets.

mms

DOI [BibTex]

DOI [BibTex]


{Real-space imaging of confined magnetic skyrmion tubes}
Real-space imaging of confined magnetic skyrmion tubes

Birch, M. T., Cortés-Ortuño, D., Turnbull, L. A., Wilson, M. N., Groß, F., Träger, N., Laurenson, A., Bukin, N., Moody, S. H., Weigand, M., Schütz, G., Popescu, H., Fan, R., Steadman, P., Verezhak, J. A. T., Balakrishnan, G., Loudon, J. C., Twitchett-Harrison, A. C., Hovorka, O., Fangohr, H., Ogrin, F., Gräfe, J., Hatton, P. D.

Nature Communications, 11, pages: 1726, 2020 (article)

Abstract
Magnetic skyrmions are topologically nontrivial particles with a potential application as information elements in future spintronic device architectures. While they are commonly portrayed as two dimensional objects, in reality magnetic skyrmions are thought to exist as elongated, tube-like objects extending through the thickness of the host material. The study of this skyrmion tube state (SkT) is vital for furthering the understanding of skyrmion formation and dynamics for future applications. However, direct experimental imaging of skyrmion tubes has yet to be reported. Here, we demonstrate the real-space observation of skyrmion tubes in a lamella of FeGe using resonant magnetic x-ray imaging and comparative micromagnetic simulations, confirming their extended structure. The formation of these structures at the edge of the sample highlights the importance of confinement and edge effects in the stabilisation of the SkT state, opening the door to further investigation into this unexplored dimension of the skyrmion spin texture.

mms

link (url) DOI [BibTex]

link (url) DOI [BibTex]


no image
Current-induced dynamical tilting of chiral domain walls in curved microwires

Finizio, S., Wintz, S., Mayr, S., Huxtable, A. J., Langer, M., Bailey, J., Burnell, G., Marrows, C. H., Raabe, J.

Applied Physics Letters, 116(18), American Institute of Physics, Melville, NY, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Highly effective hydrogen isotope separation through dihydrogen bond on Cu(I)-exchanged zeolites well above liquid nitrogen temperature

Xiong, R., Zhang, L., Li, P., Luo, W., Tang, T., Ao, B., Sang, G., Chen, C., Yan, X., Chen, J., Hirscher, M.

Chemical Engineering Journal, 391, Elsevier, Lausanne, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Ferrimagnetic skyrmions in topological insulator/ferrimagnet heterostructures

Wu, H., Groß, F., Dai, B. Q., Lujan, D., Razavi, S. A., Zhang, P., Liu, Y. X., Sobotkiewich, K., Förster, J., Weigand, M., Schütz, G., Li, X. Q., Gräfe, J., Wang, K. L.

Advanced Materials, 32(34), Wiley-VCH, Weinheim, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Spin-Bahn-Effekte in der Vortexdynamik und kürzeste Spinwellen in Y3Fe5O12

Förster, J.

Universität Stuttgart, Stuttgart (und Cuvillier Verlag, Göttingen), 2020 (phdthesis)

mms

[BibTex]

[BibTex]


no image
Highly nonlinear magnetoelectric effect in buckled-honeycomb antiferromagnetic Co4Ta2O9

Lee, N., Oh, D. G., Choi, S., Moon, J. Y., Kim, J. H., Shin, H. J., Son, K., Nuss, J., Kiryukhin, V., Choi, Y. J.

Scientific Reports, 10, Nature Publishing Group, London, UK, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Room temperature ferromagnetism driven by Ca-doped BiFeO3 multiferroic functional material

Marzouk, M., Hashem, H. M., Soltan, S., Ramadan, A. A.

{Journal of Materials Science: Materials in Electronics}, 31(7):5599-5607, Springer, Norwell, MA, 2020 (article)

mms

DOI [BibTex]

DOI [BibTex]