Removal of electrostatic artifacts in magnetic force microscopy by controlled magnetization of the tip: application to superparamagnetic nanoparticles

The most outstanding feature of scanning force microscopy (SFM) is its capability to detect various different short and long range interactions. In particular, magnetic force microscopy (MFM) is used to characterize the domain configuration in ferromagnetic materials such as thin films grown by physical techniques or ferromagnetic nanostructures. It is a usual procedure to separate the topography and the magnetic signal by scanning at a lift distance of 25–50 nm such that the long range tip–sample interactions dominate. Nowadays, MFM is becoming a valuable technique to detect weak magnetic fields arising from low dimensional complex systems such as organic nanomagnets, superparamagnetic nanoparticles, carbon-based materials, etc. In all these cases, the magnetic nanocomponents and the substrate supporting them present quite different electronic behavior, i.e., they exhibit large surface potential differences causing heterogeneous electrostatic interaction between the tip and the sample that could be interpreted as a magnetic interaction. To distinguish clearly the origin of the tip–sample forces we propose to use a combination of Kelvin probe force microscopy (KPFM) and MFM. The KPFM technique allows us to compensate in real time the electrostatic forces between the tip and the sample by minimizing the electrostatic contribution to the frequency shift signal. This is a great challenge in samples with low magnetic moment. In this work we studied an array of Co nanostructures that exhibit high electrostatic interaction with the MFM tip. Thanks to the use of the KPFM/MFM system we were able to separate the electric and magnetic interactions between the tip and the sample.

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Magnetic Force Microscopy of Superparamagnetic Nanoparticles

Small ◽

10.1002/smll.200700116 ◽

2008 ◽

Vol 4 (2) ◽

pp. 270-278 ◽

Cited By ~ 74

Author(s):

Sharon Schreiber ◽

Mayur Savla ◽

Denis V. Pelekhov ◽

Daniel F. Iscru ◽

Camelia Selcu ◽

...

Keyword(s):

Magnetic Force Microscopy ◽

Magnetic Force ◽

Superparamagnetic Nanoparticles ◽

Force Microscopy

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Influence of dielectric layer thickness and roughness on topographic effects in magnetic force microscopy

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.10.106 ◽

2019 ◽

Vol 10 ◽

pp. 1056-1064 ◽

Cited By ~ 3

Author(s):

Alexander Krivcov ◽

Jasmin Ehrler ◽

Marc Fuhrmann ◽

Tanja Junkers ◽

Hildegard Möbius

Keyword(s):

Layer Thickness ◽

Dielectric Layer ◽

Magnetic Force Microscopy ◽

Magnetic Force ◽

Capacitive Coupling ◽

Superparamagnetic Nanoparticles ◽

Topographic Effects ◽

Point Dipole ◽

Magnetic Signal ◽

Force Microscopy

Magnetic force microscopy (MFM) has become a widely used tool for the characterization of magnetic properties. However, the magnetic signal can be overlapped by additional forces acting on the tip such as electrostatic forces. In this work the possibility to reduce capacitive coupling effects between tip and substrate is discussed in relation to the thickness of a dielectric layer introduced in the system. Single superparamagnetic iron oxide nanoparticles (SPIONs) are used as a model system, because their magnetic signal is contrariwise to the signal due to capacitive coupling so that it is possible to distinguish between magnetic and electric force contributions. Introducing a dielectric layer between substrate and nanoparticle the capacitive coupling can be tuned and minimized for thick layers. Using the theory of capacitive coupling and the magnetic point dipole–dipole model we could theoretically explain and experimentally prove the phase signal for single superparamagnetic nanoparticles as a function of the layer thickness of the dielectric layer. Tuning the capacitive coupling by variation of the dielectric layer thickness between nanoparticle and substrate allows the distinction between the electric and the magnetic contributions to the MFM signal. The theory also predicts decreasing topographic effects in MFM signals due to surface roughness of dielectric films with increasing film thickness.

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Magnetic Force Microscopy Studies of Superparamagnetic Nanoparticles

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/18/2/022019 ◽

2011 ◽

Vol 18 (2) ◽

pp. 022019 ◽

Cited By ~ 1

Author(s):

B Bittova ◽

J P Vejpravova ◽

A Mantlikova

Keyword(s):

Magnetic Force Microscopy ◽

Magnetic Force ◽

Superparamagnetic Nanoparticles ◽

Force Microscopy

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Magnetic anisotropy considerations in magnetic force microscopy studies of single superparamagnetic nanoparticles

Nanotechnology ◽

10.1088/0957-4484/23/49/495704 ◽

2012 ◽

Vol 23 (49) ◽

pp. 495704 ◽

Cited By ~ 30

Author(s):

Tanya M Nocera ◽

Jun Chen ◽

Christopher B Murray ◽

Gunjan Agarwal

Keyword(s):

Magnetic Anisotropy ◽

Magnetic Force Microscopy ◽

Magnetic Force ◽

Superparamagnetic Nanoparticles ◽

Force Microscopy

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Study of MFM Application in Semiconductor Failure Analysis

ISTFA 2004: Conference Proceedings from the 30th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2004p0353 ◽

2004 ◽

Author(s):

Way-Jam Chen ◽

Lily Shiau ◽

Ming-Ching Huang ◽

Chia-Hsing Chao

Keyword(s):

Magnetic Field ◽

Failure Analysis ◽

Magnetic Force Microscopy ◽

Magnetic Force ◽

Current Flow ◽

Force Microscopy ◽

The Magnetic Field ◽

A Current

Abstract In this study we have investigated the magnetic field associated with a current flowing in a circuit using Magnetic Force Microscopy (MFM). The technique is able to identify the magnetic field associated with a current flow and has potential for failure analysis.

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Magnetic Force Microscopy: Comparison and Validation of Different Magnetic Force Microscopy Calibration Schemes (Small 11/2020)

Small ◽

10.1002/smll.202070058 ◽

2020 ◽

Vol 16 (11) ◽

pp. 2070058

Author(s):

Héctor Corte‐León ◽

Volker Neu ◽

Alessandra Manzin ◽

Craig Barton ◽

Yuanjun Tang ◽

...

Keyword(s):

Magnetic Force Microscopy ◽

Magnetic Force ◽

Force Microscopy

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Magnetic Domain Observation on Melt-Spun Nd-Fe-B Ribbons Using Magnetic Force Microscopy

MRS Proceedings ◽

10.1557/proc-577-241 ◽

1999 ◽

Vol 577 ◽

Author(s):

A. Gavrin ◽

C. Sellers ◽

S.H. Liouw

Keyword(s):

Magnetic Force Microscopy ◽

Magnetic Force ◽

Magnetic Measurements ◽

Magnetic Domain ◽

Domain Size ◽

High Coercivity ◽

Uniform Domain ◽

Cross Sectional ◽

Force Microscopy ◽

Melt Spun

ABSTRACTWe have used Magnetic Force Microscopy (MFM) to study the magnetic domain structures of melt-spun Nd-Fe-B ribbons. The ribbons are commercial products (Magnequench International, Inc. MQP-B and MQP-B+) with a thickness of approximately 20 microns. These materials have identical composition, Nd12.18B5.36Fe76.99Co5.46, but differ in quenching conditions. In order to study the distribution of domain sizes through the ribbon thickness, we have prepared cross-sectional samples in epoxy mounts. In order to avoid artifacts due to tip-sample interactions, we have used high coercivity CoPt coated MFM tips. Our studies show domain sizes typically ranging from 50-200 nm in diameter. This is in agreement with studies of similar materials in which domains were investigated in the plane of the ribbon. We also find that these products differ substantially in mean domain size and in the uniformity of the domain sizes as measured across the ribbon. While the B+ material shows nearly uniform domain sizes throughout the cross section, the B material shows considerably larger domains on one surface, followed by a region in which the domains are smaller than average. This structure is presumably due to the differing quench conditions. The region of coarse domains varies in thickness, disappearing in some areas, and reaching a maximum thickness of 2.75 µm in others. We also describe bulk magnetic measurements, and suggest that.

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