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/.

Magnetization-polarization cross-control near room temperature in hexaferrite single crystals

In their publication “Magnetization-polarization cross-control near room temperature in hexaferrite single crystals” V. Kocsis, T. Nakajima, M. Matsuda, A. Kikkawa, Y. Kaneko, J. Takashima, K. Kakurai, T. Arima, F. Kagawa, Y. Tokunaga, Y. Tokura and Y. Taguchi report that they have successfully stabilized a simultaneously ferrimagnetic and ferroelectric phase in a Y-type hexaferrite single crystal up to 450 K, and demonstrated the reversal of large non-volatile M by E field close to room temperature. Manipulation of the magnetic domains by E field was directly visualized at room temperature by using magnetic force microscopy.*

NanoWorld MFMR AFM probes with a hard magnetic coating were used for the magnetic force microscopy measurements described in this article.

Figure 5 from “Magnetization-polarization cross-control near room temperature in hexaferrite single crystals” by V. Kocsis et al.: Real-space magnetic force microscopy (MFM) images. The MFM images were taken on the same 10 × 10 μm2 region of a BSCFAO crystal with an ac face (see Supplementary Figs. 3, 9 and 10) at room temperature. Prior to the MFM measurements, the sample was poled to a single-domain ME state using (+E0, +H0) poling fields in a E ⊥ H; E, H ⊥ c configuration. Panel a shows the changes in the magnetic domain pattern caused by two successive applications of the E field with different signs (the initial state is labeled as the 0th). The images include small regions, R1 and R2, where two representative cases of DW motion are observed. Around R1, the negatively magnetized domain (denoted with blue color, MFM phase shift Δφ < 0) expands and shrinks along the c-axis upon the first and second applications of E-field, respectively. On the other hand, around R2, a positively magnetized domain (denoted with red color, Δφ > 0) is pushed into the view area from the upper side along the ab plane. These two cases are further displayed as line profiles of the MFM phase shift (Δφ) data along the b A−A′ and c B−B′ lines. Panels d, e show the schematic illustration of these two cases of domain wall motions for the second E-field switch, respectively. NanoWorld MFMR AFM probes were used for the magnetic force microscopy.
Figure 5 from “Magnetization-polarization cross-control near room temperature in hexaferrite single crystals” by V. Kocsis et al.: Real-space magnetic force microscopy (MFM) images. The MFM images were taken on the same 10 × 10 μm2 region of a BSCFAO crystal with an ac face (see Supplementary Figs. 3, 9 and 10) at room temperature. Prior to the MFM measurements, the sample was poled to a single-domain ME state using (+E0, +H0) poling fields in a E ⊥ H; E, H ⊥ c configuration. Panel a shows the changes in the magnetic domain pattern caused by two successive applications of the E field with different signs (the initial state is labeled as the 0th). The images include small regions, R1 and R2, where two representative cases of DW motion are observed. Around R1, the negatively magnetized domain (denoted with blue color, MFM phase shift Δφ < 0) expands and shrinks along the c-axis upon the first and second applications of E-field, respectively. On the other hand, around R2, a positively magnetized domain (denoted with red color, Δφ > 0) is pushed into the view area from the upper side along the ab plane. These two cases are further displayed as line profiles of the MFM phase shift (Δφ) data along the b A−A′ and c B−B′ lines. Panels d, e show the schematic illustration of these two cases of domain wall motions for the second E-field switch, respectively.

*V. Kocsis, T. Nakajima, M. Matsuda, A. Kikkawa, Y. Kaneko, J. Takashima, K. Kakurai, T. Arima, F. Kagawa, Y. Tokunaga, Y. Tokura, Y. Taguchi
Magnetization-polarization cross-control near room temperature in hexaferrite single crystals
Nature Communications, volume 10, Article number: 1247 (2019)
DOI: https://doi.org/10.1038/s41467-019-09205-x

Please follow this external link to the full article: https://www.nature.com/articles/s41467-019-09205-x

Open Access The article ” Magnetization-polarization cross-control near room temperature in hexaferrite single crystals” by V. Kocsis et al. 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/.