Tag Archives: MFMプローブ

Magnetic Skyrmions in a Thickness Tunable 2D Ferromagnet from a Defect Driven Dzyaloshinskii–Moriya Interaction

There is considerable interest in van der Waals (vdW) materials as potential hosts for chiral skyrmionic spin textures. Of particular interest is the ferromagnetic, metallic compound Fe3GeTe2 (FGT), which has a comparatively high Curie temperature (150–220 K). Several recent studies have reported the observation of chiral Néel skyrmions in this compound, which is inconsistent with its presumed centrosymmetric structure.*

In the article “Magnetic Skyrmions in a Thickness Tunable 2D Ferromagnet from a Defect Driven Dzyaloshinskii–Moriya Interaction” Anirban Chakraborty, Abhay K. Srivastava, Ankit K. Sharma, Ajesh K. Gopi, Katayoon Mohseni, Arthur Ernst, Hakan Deniz, Binoy Krishna Hazra, Souvik Das, Paolo Sessi, Ilya Kostanovskiy, Tianping Ma, Holger L. Meyerheim and Stuart S. P. Parkin report  the observation of Néel type skyrmions in single crystals of FGT via Lorentz transmission electron microscopy (LTEM).*

Since LTEM requires transmission of electrons through the sample thickness, the authors investigated the thicker lamella L2 using only magnetic force microscopy (MFM). *
For MFM measurements, the lamella was transferred on a prepatterned silicon substrate to be easily accessible by MFM tip. The measurements were performed in a vacuum and NANOSENSORS™ SuperSharpSilicon™ AFM probes for magnetic force microscopy (SSS-MFMR) were used for all measurements. *

In the article it is shown from detailed X-ray diffraction structure analysis that FGT lacks an inversion symmetry as a result of an asymmetric distribution of Fe vacancies. This vacancy-induced breaking of the inversion symmetry of this compound is a surprising and novel observation and is a prerequisite for a Dzyaloshinskii–Moriya vector exchange interaction which accounts for the chiral Néel skyrmion phase. This phenomenon is likely to be common to many 2D vdW materials and suggests a path to the preparation of many such acentric compounds. *

Furthermore, it is found that the skyrmion size in FGT is strongly dependent on its thickness: the skyrmion size increases from ≈100 to ≈750 nm as the thickness of the lamella is increased from ≈90 nm to ≈2 µm. This extreme size tunability is a feature common to many low symmetry ferro- and ferri-magnetic compounds. *

Figure 4 from “Magnetic Skyrmions in a Thickness Tunable 2D Ferromagnet from a Defect Driven Dzyaloshinskii–Moriya Interaction” by Anirban Chakraborty et al. Thickness dependence of skyrmion size in lamella L2 as imaged by MFM. a) SEM image of the wedge-shaped lamella. The thickness of the lamella varies from ≈100 nm to ≈2 µm. b) MFM image of skyrmions in the lamella at 100 K and 0.032 T. c–f) Evolution of skyrmions as the field is increased from 0.1 to 0.2 T and finally reaches the field polarized state at ≈0.3 T. The blue and red contrast in the MFM images represent up- and down-magnetized domains. All MFM images are at the same scale: a scale bar is shown in (b). g) Skyrmion diameter as a function of lamella thickness including both MFM and LTEM data. NANOSENSORS SSS-MFMR AFM probes for magnetic force microscopy were used for all MFM measurements.
Figure 4 from “Magnetic Skyrmions in a Thickness Tunable 2D Ferromagnet from a Defect Driven Dzyaloshinskii–Moriya Interaction” by Anirban Chakraborty et al.
Thickness dependence of skyrmion size in lamella L2 as imaged by MFM. a) SEM image of the wedge-shaped lamella. The thickness of the lamella varies from ≈100 nm to ≈2 µm. b) MFM image of skyrmions in the lamella at 100 K and 0.032 T. c–f) Evolution of skyrmions as the field is increased from 0.1 to 0.2 T and finally reaches the field polarized state at ≈0.3 T. The blue and red contrast in the MFM images represent up- and down-magnetized domains. All MFM images are at the same scale: a scale bar is shown in (b). g) Skyrmion diameter as a function of lamella thickness including both MFM and LTEM data.

*Anirban Chakraborty, Abhay K. Srivastava, Ankit K. Sharma, Ajesh K. Gopi, Katayoon Mohseni, Arthur Ernst, Hakan Deniz, Binoy Krishna Hazra, Souvik Das, Paolo Sessi, Ilya Kostanovskiy, Tianping Ma, Holger L. Meyerheim and Stuart S. P. Parkin
Magnetic Skyrmions in a Thickness Tunable 2D Ferromagnet from a Defect Driven Dzyaloshinskii–Moriya Interaction
Advanced Materials, Volume 34, Issue 11, March 17, 2022, 2108637
DOI: https://doi.org/10.1002/adma.202108637

Open Access: The article “Magnetic Skyrmions in a Thickness Tunable 2D Ferromagnet from a Defect Driven Dzyaloshinskii–Moriya Interaction” by Anirban Chakraborty, Abhay K. Srivastava, Ankit K. Sharma, Ajesh K. Gopi, Katayoon Mohseni, Arthur Ernst, Hakan Deniz, Binoy Krishna Hazra, Souvik Das, Paolo Sessi, Ilya Kostanovskiy, Tianping Ma, Holger L. Meyerheim and Stuart S. P. Parkin is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/.

NANOSENSORS AFM probes for Magnetic Force Microscopy

Did you know that NANOSENSORS offers six different types of AFM probes for Magnetic Force Microscopy ( MFM) for scanning and investigating sample surfaces with magnetic features?

PPP-MFMR – AFM tip with hard magnetic coating, sensitivity, resolution and coercivity designed for standard magnetic force microscopy applications

PPP-LM-MFMR – designed for magnetic force microscopy with reduced disturbance of the magnetic sample by the MFM tip and enhanced lateral resolution

PPP-LC-MFMR –  MFM tip with soft magnetic coating designed for the measurement of magnetic domains in soft magnetic samples

PPP-QLC-MFMR –  low coercivity MFM probe designed for high operation stability and low disturbance of magnetic samples under ultrahigh vacuum ( UHV ) conditions

SSS-MFMR – SuperSharp MFM probe for high resolution magnetic force imaging, low magnetic moment for reduced disturbance of soft magnetic samples

SSS-QMFMR – SuperSharp MFM probe for high resolution magnetic force imaging with a high mechanical Q-factor for applications in ultrahigh vacuum ( UHV ) .

The screencast introducing all these different MFM probes, their properties and their applications held by our Head of R&D Thomas Sulzbach has just passed the 1500 views mark. Congratulations Thomas!

NANOSENSORS AFM tips for Magnetic Force Microscopy

For further details please have a look at the NANOSENSORS MFM probes brochure.

Application examples for NANOSENSORS AFM probes for Magnetic Force Microscopy can be found in the NANOSENSORS blog.

NANOSENSORS screencasts on Magnetic Force Microscopy AFM probes are also available in

Chinese

on youku http://v.youku.com/v_show/id_XNzMyMDg2MjQ4.html

and Youtube

and

Japanese

3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation

Bone is the second most commonly transplanted tissue, preceded only by blood transfusion.Within this context, it is imperative to achieve the functional and structural restoration of damaged bone tissue. A major difficulty in bone tissue engineering arises from the fact that the bone regeneration process requires a long time for achieving a completely functional tissue. Generally, cells are seeded ex vivo into a three-dimensional (3D) biocompatible and sometimes biodegradable structure called scaffold, where they attach and grow. After the implantation into the injured site, the scaffolds should allow proper host cell colonization for regeneration purposes.*

Magnetic scaffolds emerged as promising solution for this purpose. Activation of the magnetic scaffolds using external static magnetic fields (SMF) prevents the decrease of bone mineral density and promotes the bone regeneration in bone fractures. The significant alterations in cell behaviors stimulated by the externally applied magnetic fields has been demonstrated in numerous studies. For example, it has been shown that an externally applied SMF using a magnet accelerates the osteogenic differentiation of osteoblasts-like cells in vitro and triggers peri-implant bone formation in vivo.*

The magnetism can also be used through scaffolding materials with magnetic properties. For example, biomaterials that incorporate magnetic nanoparticles (MNPs) are being developed.*

In the article «3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation” Irina Alexandra Paun, Bogdan Stefanita Calin, Cosmin Catalin Mustaciosu, Mona Mihailescu, Antoniu Moldovan, Ovidiu Crisan, Aurel Leca and Catalin Romeo Luculescu report on three-dimensional (3D) superparamagnetic scaffolds that enhanced the mineralization of magnetic nanoparticle-free osteoblast cells. The scaffolds were fabricated with submicronic resolution by laser direct writing via two photons polymerization of Ormocore/magnetic nanoparticles (MNPs) composites and possessed complex and reproducible architectures.*

To prove the magnetic nature of the MNPs in the polymerized composites, magnetic force microscopy (MFM) was carried out on scaffolds with different MNPs concentrations. NANOSENSORS™ PointProbe® Plus PPP-MFMR AFM probes with magnetic coating were used.*

Figure 5 from “3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation” by Irina Alexandra Paun et al:
Topographical (upper panel) and magnetic force microscopy (lower panel) images of scaffolds with MNPs concentrations of: (a,d) 0 mg/mL; (b,e) 2 mg/mL; (c,f) 4 mg/mL.

*Irina Alexandra Paun, Bogdan Stefanita Calin, Cosmin Catalin Mustaciosu, Mona Mihailescu, Antoniu Moldovan, Ovidiu Crisan, Aurel Leca and Catalin Romeo Luculescu
3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation
Materials 2019, 12(17), 2834
DOI: https://doi.org/10.3390/ma12172834

Please follow this link to read the full article: https://www.mdpi.com/1996-1944/12/17/2834/htm

Open Access The article “3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation” by Irina Alexandra Paun, Bogdan Stefanita Calin, Cosmin Catalin Mustaciosu, Mona Mihailescu, Antoniu Moldovan, Ovidiu Crisan, Aurel Leca and Catalin Romeo Luculescu is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.