Magnetic AFM Probes

Magnetic AFM probes are intended to be used for Magnetic Force Microscopy (MFM). For that purpose, their AFM tip is coated with a magnetic thin film creating a magnetic stray field that interacts with magnetic fields of the sample under investigation. Therefore, this technique allows high-resolution visualization of magnetic domains at the sample.

The measurement technique is usually based on dual surface scan. The first scan detects the surface topography in the same way as standard AFM applications would do. Afterwards the surface is scanned a second time but at a pre-defined distance to the surface (lift height). This second scan detects magnetic interactions between the magnetized AFM tip and the magnetic domains of the sample. The separation of information is achieved by using short-range mechanical forces for surface detection and long-range magnetic forces for visualization of magnetic domains.

Magnetic Force Microscopy is usually performed under ambient conditions although it can be done in vacuum or within liquids, as well. The samples under investigation need not be electrically conductive and sample preparation is not necessary. A thin cover layer protecting the magnetic layer has almost no impact on the measurement result. Applying an external field for modification of sample domains is possible, as well, as long as the AFM tip magnetization is not affected by the external field.

In order to facilitate this measurement mode, the magnetic AFM probes combine good force sensitivity with sufficient stability for dynamic mode operation. The AFM cantilevers are soft enough to detect smallest forces, but their force constant is large enough to prevent snap-in effects under ambient conditions. The AFM tip will not stick at the surface during operation.

As the visualization of magnetic domains is based on the interaction between magnetic stray fields of sample and AFM tip, respectively, achievable lateral resolution, sensitivity and stability of AFM measurement operation depends on both, magnetic properties of AFM tip and sample. In general, a strong AFM tip stray field enhances sensitivity and leads to increased signal. But, on the other hand, a strong AFM tip stray field may modify the magnetic domains at the sample surface. In the worst case, the domains are wiped away by the AFM tip during scanning and the magnetic domain structure is not visible in the image, at all. If the magnetic domains at the sample are a bit more stable local changes induced by the AFM tip stray field will lead to disturbed AFM imaging.

In the opposite case, if the sample stray fields are strong enough the AFM tip magnetization may change during the scan leading to disturbed AFM imaging, as well. Therefore, the magnetic AFM probe type must be chosen carefully according to the requirements of application. Generally, AFM tip magnetization should be chosen as large as the sample allows.

Another aspect of selecting the optimal magnetic AFM tip for a specific application is related to the achievable resolution. Usually, the strength of AFM tip magnetization is correlated with the volume of magnetic material at the AFM tip which is correlated with the AFM tip diameter. Therefore, magnetic sensitivity of magnetic AFM probes decreases with achievable lateral resolution. A trade-off between signal strength and lateral resolution must be found. A thicker magnetic coating on the AFM tip leads to greater magnetic signal strength but the thicker coating also leads to a bigger AFM tip radius and therefore less lateral resolution. On the other hand, a smaller AFM tip radius with less magnetic coating material on the AFM tip will lead to a higher lateral resolution but the strength of the magnetic signal will be less.

For covering as many potential applications as possible a wide range of magnetic AFM probes with soft and hard magnetic coatings is offered by the manufactures NANOSENSORS™, NanoWorld®, BudgetSensors®, MikroMasch® and OPUS by µmasch®. The magnetic coatings involve coercivities ranging from 7.5 to 300 Oersted and a magnetization of 80 emu/cm³ to 300 emu/cm³. A lateral AFM measurement resolution down to 25nm can be achieved.

For application in ultra-high vacuum (UHV) especially tailored magnetic AFM probes fabricated by NANOSENSORS™ are available that enhance the Q-factor in vacuum drastically.

Magnetic AFM probes are reliably used by many scientists around the world for investigating magnetic properties of various samples. Visualization of domain walls (Bloch and Neel), closure domains, recorded magnetic bits and other magnetic patterns have been demonstrated. Typical samples are thin films, nanoparticles, nanowires, permalloy disks and recording media but also investigations at magnetic material of organic nature have been reported. The field of application is as wide as the range of magnetic phenomena and their technical application.

Magnetic Force Microscopy enables in-depth investigation of magnetism on the nanometer scale and the wide range of available magnetic AFM probe types facilitates its usage for numerous application topics.
15 results matching your criteria
best of the best
PPP-MFMR

PPP-MFMR

Hard Magnetic, Medium Momentum MFM AFM Probe
Coating: Magnetic
Tip Shape: Standard
AFM Cantilever:
F
75 kHz
C
2.8 N/m
L
225 µm
SSS-MFMR

SSS-MFMR

SuperSharp, Hard Magnetic, Low Momentum MFM AFM Probe
Coating: Magnetic
Tip Shape: Supersharp
AFM Cantilever:
F
75 kHz
C
2.8 N/m
L
225 µm
the industry standard
MFMR

MFMR

Hard Magnetic, Medium Momentum MFM AFM Probe
Coating: Magnetic
Tip Shape: Standard
AFM Cantilever:
F
75 kHz
C
2.8 N/m
L
225 µm
S-MFMR

S-MFMR

Soft Magnetic, Medium Momentum MFM AFM Probe
Coating: Magnetic
Tip Shape: Standard
AFM Cantilever:
F
75 kHz
C
2.8 N/m
L
225 µm
top value
HQ:NSC18/Co-Cr/Al BS

HQ:NSC18/Co-Cr/Al BS

Hard Magnetic, Medium Momentum MFM AFM Probe
Coating: Magnetic
Tip Shape: Rotated
AFM Cantilever:
F
75 kHz
C
2.8 N/m
L
225 µm
HQ:NSC36/Co-Cr/Al BS

HQ:NSC36/Co-Cr/Al BS

Hard Magnetic, Medium Momentum MFM AFM Probe with 3 Different AFM Cantilevers
Coating: Magnetic
Tip Shape: Rotated
AFM Cantilevers: 3
1
2
3
F
60 kHz
130 kHz
65 kHz
C
1 N/m
2 N/m
0.6 N/m
L
110 µm
90 µm
130 µm
Mix and Match Box

Mix and Match Box

Mixed box: up to 400 MikroMasch AFM probes
Coating: various
Tip Shape: various
top value
240AC-MA

240AC-MA

Hard Magnetic, Medium Momentum AFM Probe with AFM Tip at the Very End of the AFM Cantilever
Coating: Magnetic
Tip Shape: OPUS
AFM Cantilever:
F
70 kHz
C
2 N/m
L
240 µm
best bang for your buck
MagneticMulti75-G

MagneticMulti75-G

Hard Magnetic, Medium Momentum AFM Probe
Coating: Magnetic
Tip Shape: Rotated
AFM Cantilever:
F
75 kHz
C
3 N/m
L
225 µm
SSS-QMFMR

SSS-QMFMR

SuperSharp, Hard Magnetic, Low Momentum MFM AFM Probe with a High Mechanical Q-Factor
Coating: Magnetic
Tip Shape: Supersharp
AFM Cantilever:
F
75 kHz
C
2.8 N/m
L
225 µm
PPP-LM-MFMR

PPP-LM-MFMR

Hard Magnetic, Low Momentum MFM AFM Probe
Coating: Magnetic
Tip Shape: Standard
AFM Cantilever:
F
75 kHz
C
2.8 N/m
L
225 µm
PPP-LC-MFMR

PPP-LC-MFMR

Soft Magnetic, Medium Momentum MFM AFM Probe
Coating: Magnetic
Tip Shape: Standard
AFM Cantilever:
F
75 kHz
C
2.8 N/m
L
225 µm
PPP-QLC-MFMR

PPP-QLC-MFMR

Soft Magnetic, Medium Momentum MFM AFM Probe with a High Mechanical Q-Factor
Coating: Magnetic
Tip Shape: Standard
AFM Cantilever:
F
75 kHz
C
2.8 N/m
L
225 µm
BudgetComboBox

BudgetComboBox

Mixed Box with 50 BudgetSensors AFM probes of your choice
Coating: various
Tip Shape: various
Special Developments List

Special Developments List

Download a List of Non-Standard, Special AFM Probes and More

Coating: various
Tip Shape: various
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