Nanoscale Noncollinear Spin Textures in Thin Films of a D2d Heusler Compound

Magnetic nano-objects, namely antiskyrmions and Bloch skyrmions, have been found to coexist in single-crystalline lamellae formed from bulk crystals of inverse tetragonal Heusler compounds with D2d symmetry. *

Skyrmions can be observed in real-space by various direct imaging techniques. *

In the article “Nanoscale Noncollinear Spin Textures in Thin Films of a D2d Heusler Compound”  Ankit K. Sharma, Jagannath Jena, Kumari Gaurav Rana, Anastasios Markou, Holger L. Meyerheim, Katayoon Mohseni, Abhay K. Srivastava, Ilya Kostanoskiy, Claudia Felser and Stuart S. P. Parkin  describe the use of magnetic force microscopy (MFM) imaging to investigate magnetic textures in epitaxial thin films of [001]-oriented Mn2RhSn formed by magnetron sputtering.*

They find evidence for magnetic nano-objects which exhibit a wide range of sizes with stability with respect to magnetic field and temperature that is similar to single-crystalline lamellae. *

However, the nano-objects do not form well-defined arrays, nor is any evidence found for helical spin textures. This is speculated to likely be a consequence of the poorer homogeneity of chemical ordering in the thin films. *

Evidence is found for elliptically distorted nano-objects along perpendicular crystallographic directions within the epitaxial films, which is consistent with elliptical Bloch skyrmions observed in single-crystalline lamellae. Thus, these measurements provide strong evidence for the formation of noncollinear spin textures in thin films of Mn2RhSn. *

Using these films, it is shown that individual nano-objects can be deleted using a local magnetic field from a magnetic AFM tip and collections of nano-objects can be similarly written. *

For writing and deleting the nano-objects, magnetic AFM probes from NanoWorld of the Pointprobe® MFMR type were used. *

These observations described in the article suggest a path toward the use of these nano-objects in thin films with D2d symmetry as magnetic memory elements paving the way to the realization of skyrmionic devices based on Heusler thin films. *

Figure 5 from Ankit K. Sharma et al. Nanoscale Noncollinear Spin Textures in Thin Films of a D2d Heusler Compound : Controlled creation and annihilation of nano-objects in a 35 nm-thick Mn2RhSn thin film. a) Schematic illustration of magnetization orientations of MFM tip and sample for writing. The distance between tip and the sample is the scan height z. b–e) MFM images in zero field and z = 80, 40, 30, and 20 nm, respectively at 200 K. f) Contact-mode image in zero field and 200 K. The blue and red colors represent up and down magnetization, respectively. Images in (b)–(f) are at the same scale: a scale bar is given in (f). g–i) MFM images taken at z = 70, 50, and 30 nm at 100 K under Hz = 180 mT. Images in (g)–(i) are at the same scale: a scale bar is given in (i). For writing and deleting the nano-objects, magnetic AFM probes from NanoWorld of the Pointprobe® MFMR type were used.
Figure 5 from Ankit K. Sharma et al. Nanoscale Noncollinear Spin Textures in Thin Films of a D2d Heusler Compound :
Controlled creation and annihilation of nano-objects in a 35 nm-thick Mn2RhSn thin film. a) Schematic illustration of magnetization orientations of MFM tip and sample for writing. The distance between tip and the sample is the scan height z. b–e) MFM images in zero field and z = 80, 40, 30, and 20 nm, respectively at 200 K. f) Contact-mode image in zero field and 200 K. The blue and red colors represent up and down magnetization, respectively. Images in (b)–(f) are at the same scale: a scale bar is given in (f). g–i) MFM images taken at z = 70, 50, and 30 nm at 100 K under Hz = 180 mT. Images in (g)–(i) are at the same scale: a scale bar is given in (i).

*Ankit K. Sharma, Jagannath Jena, Kumari Gaurav Rana, Anastasios Markou, Holger L. Meyerheim, Katayoon Mohseni, Abhay K. Srivastava, Ilya Kostanoskiy, Claudia Felser, Stuart S. P. Parkin
Nanoscale Noncollinear Spin Textures in Thin Films of a D2d Heusler Compound
Advanced Materials, Volume 33, Issue 32, August 12, 2021, 2101323
DOI: https://doi.org/10.1002/adma.202101323

Open Access The article “Nanoscale Noncollinear Spin Textures in Thin Films of a D2d Heusler Compound” Ankit K. Sharma, Jagannath Jena, Kumari Gaurav Rana, Anastasios Markou, Holger L. Meyerheim, Katayoon Mohseni, Abhay K. Srivastava, Ilya Kostanoskiy, Claudia Felser 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 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/.

AFM probes for Magnetic Force Microscopy – screencast on NanoWorld MFM tips passes 2000 views mark

The screencast about NanoWorld AFM probes for Magnetic Force Microscopy held by Dr. Marco Becker has just passed the 2000 views mark. Congratulations Marco!

Magnetic Force Microscopy is a type of Atomic Force Microscopy in which a magnetised AFM tip is used to measure magnetic interactions between the tip and the surface of a magnetic sample. These detected interactions are then used to reconstruct the magnetic structure of the sample surface

NanoWorld currently offers two types of MFM tips:

MFMR – This type of magnetic AFM tip is coated with a hard magnetic coating on the tip side and yields a very high force sensitivity, while simultaneously enabling tapping and lift mode operation.

S-MFMR – These magnetic AFM tips are coated with a soft magnetic layer on the tip side and are designed for the measurement of magnetic domains in soft magnetic samples.

Magnetic reversal in perpendicularly magnetized antidot arrays with intrinsic and extrinsic defects

Defects can significantly affect performance of nanopatterned magnetic devices, therefore their influence on the material properties has to be understood well before the material is used in technological applications. However, this is experimentally challenging due to the inability of the control of defect characteristics in a reproducible manner.*

In “Magnetic reversal in perpendicularly magnetized antidot arrays with intrinsic and extrinsic defects» Michal Krupinski, Pawel Sobieszczyk, Piotr Zieliński and Marta Marszałek construct a micromagnetic model, which accounts for intrinsic and extrinsic defects associated with the polycrystalline nature of the material and with corrugated edges of nanostructures.*

The findings described in their article show that magnetic properties and domain configuration in nanopatterned systems are strongly determined by the defects, the heterogeneity of the nanostructure sizes and edge corrugations, and that such imperfections play a key role in the processes of magnetic reversal.*

The magnetic imaging described in the article cited above was performed using NanoWorld MFMR AFM probes for magnetic force microscopy (MFMR).

Figure 8 from “Magnetic reversal in perpendicularly magnetized antidot arrays with intrinsic and extrinsic defects” by Michal Krupinski et al.:
(a) MFM image for an array with an antidot diameter 182 nm taken in zero field after ac demagnetization. Selected domain walls were marked with a blue line. (b) Simulated MFM image for an antidot diameter of 185 nm corresponding to the magnetic moment configuration depicted in Fig. 6b. The MFM tip distance from the sample surface was 180 nm.
Figure 8 from “Magnetic reversal in perpendicularly magnetized antidot arrays with intrinsic and extrinsic defects” by Michal Krupinski et al.:
(a) MFM image for an array with an antidot diameter 182 nm taken in zero field after ac demagnetization. Selected domain walls were marked with a blue line. (b) Simulated MFM image for an antidot diameter of 185 nm corresponding to the magnetic moment configuration depicted in Fig. 6b. The MFM tip distance from the sample surface was 180 nm.

*Michal Krupinski, Pawel Sobieszczyk, Piotr Zieliński and Marta Marszałek
Magnetic reversal in perpendicularly magnetized antidot arrays with intrinsic and extrinsic defects
Nature Scientific Reports volume 9, Article number: 13276 (2019)
DOI: https://doi.org/10.1038/s41598-019-49869-5

Please follow this external link to read the full article https://rdcu.be/bYXYP

Open Access: The article “Magnetic reversal in perpendicularly magnetized antidot arrays with intrinsic and extrinsic defects” by Michal Krupinski, Pawel Sobieszczyk, Piotr Zieliński and Marta Marszałek 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/.