Tag Archives: Magnetic Force Microscopy

Observing single magnetite nanoparticles with a diameter of 10nm by using NANOSENSORS SSS-MFMR AFM probes

In their publication “Understanding electrostatic and magnetic forces in magnetic force microscopy: towards single supermagnetic nanoparticle resolution” Alexander Krivcov, Tanja Junkers and Hildegard Möbius describe methods to suppress capacitive coupling effects in MFM hiding the magnetic signal of magnetic nanoparticles.

During MFM measurements performed in an interleave mode moving the tip at a certain distance to the sample surface the tip is exposed not only to magnetic forces but to electrostatic forces between tip and substrates. In case of analyzing nanoparticles laying on a flat substrate, the electrostatic forces changes noticeably with increasing tip to substrate distance whenever the tip is retracted over a nanoparticle. This capacitive signal may overwhelm the magnetic signal that should be detected instead.

The authors propose several approaches to reduce these capacitive signals. The change in electrostatic forces could be minimized by avoiding retraction of tip over the nanoparticle. Therefore, it is proposed to use interleave linear mode following a linear approximation of the sample surface instead of the interleave lift mode following the sample surface as measured. By that, changes in distance between sample substrate and tip at the nanoparticles are avoided. Moreover, they propose using a substrate with a work function comparable to that of the tip in order to reduce electrostatic forces, in general. By applying an appropriate tip bias remaining electrostatic forces could compensated and further suppressed. Finally, the authors suggest using a tip that is as sharp as possible for decreasing the area of the capacitor and NANOSENSORS SSS-MFMR probes are the best choice for this.

The impact of the above mentioned optimizations have been validated experimentally by the authors. Finally, it turned out that if using super sharp magnetic tips further methods suppressing capacitive effects were not necessary. The authors were able to detect superparamagnetic nanoparticles at the single particle level on copper substrate with a NANOSENSORS SSS-MFMR probe without using additional parameters as e. g. tip bias or external magnetic field.Figure 12 from: A. Krivcov et. al, Understanding electrostatic and magnetic forces in magnetic force microscopy: towards single supermagnetic nanoparticle resolution: Figure 12. (a) topography of copper substrate with single magnetite nanoparticle; (b) phase image in 11 nm lift height with an attraction at the place of the nanoparticle; (c) Cross section of a single magnetite nanoparticle (dotted line in (a)) with 10 nm diameter taken on copper substrate with NANOSENSORS SSS-MFMR AFM probe

Figure 12  from: A. Krivcov et. al, Understanding electrostatic and magnetic forces in magnetic force microscopy: towards single supermagnetic nanoparticle resolution: Figure 12. (a) topography of copper substrate with single magnetite nanoparticle; (b) phase image in 11 nm lift height with an attraction at the place of the nanoparticle; (c) Cross section of a single magnetite nanoparticle (dotted line in (a)) with 10 nm diameter taken on copper substrate with SSS-MFMR tip

A. Krivcov, T. Junkers, and H. Möbius
Understanding electrostatic and magnetic forces in magnetic force microscopy: towards single superparamagnetic nanoparticle resolution
J. Phys. Commun., vol. 2, no. 7, p. 075019, 2018
DOI: https://doi.org/10.1088/2399-6528/aad3a4

The article “Understanding electrostatic and magnetic forces in magnetic force microscopy: towards single superparamagnetic nanoparticle resolution” by A. Krivcov, T. Junkers, and H. Möbius is licensed under the Creative Commons Attribution 3.0 License. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0.

AFM probes for Magnetic Force Microscopy Screencast passed 1000 views mark

NANOSENSORS offers six different types of AFM probes for Magnetic Force Microscopy ( MFM)  for scanning and studying sample surfaces with magnetic features:

PPP-MFMR
PPP-LM-MFMR
PPP-LC-MFMR
PPP-QLC-MFMR
SSS-MFMR
SSS-QMFMR

The screencast introducing the different properties of these AFM probes and their applications held by our Head of R&D Thomas Sulzbach has just passed the 1000 views mark. Congratulations Thomas!

NANOSENSORS 磁力显微镜探针 MFM

The screencast on NANOSENSORS AFM probes  for Magnetic Force Microscopy (MFM) is now available in Chinese on youtube  and youku

NANOSENSORS 磁力显微镜探针 MFM

在 Youtube

和在 Youku

http://v.youku.com/v_show/id_XMTQ2OTE4MzU4OA==.html?from=y1.7-1.2

本视频中介绍了NANOSENSORS公司生产的磁力显微镜探针系列 – MFM。 该探针允许在样品表面进行独立的表面形貌和磁性特征扫描,并提供不同的版本以满足不同应用需求。 其探针的磁性涂层具有优异的长效稳定性。

NANOSENSORS™的磁力显微镜探针是基于成熟的原子力显微镜探针技术。该探针具有优异的力敏感性,并可用于轻敲模式,非接触模式和空气中的抬升模 式。特别是,精心设计的悬臂的弹性系数可以使探针在保证磁性灵敏度的前提下,在各种工作模式下 (抬升模式、轻敲模式或非接触模式操作)自如地在表面扫描。