Magnetic Mode (AC)

Magnetic Force Microscopy (MFM)

Unveiling Nanoscale Magnetic Structures

Magnetic Force Microscopy (MFM) is an Atomic Force Microscopy (AFM) technique that allows for high-resolution mapping of magnetic force gradients at the nanoscale. This mode is crucial for studying magnetic materials, data storage devices, and a wide range of magnetic phenomena.

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Stainless Steel, MFM Mode Scan size 18 µm x 18 µm​

Application fields

Materials Science
Polymers
Semiconductors
2D Materials
Biology
Energy Materials

Key Features

MFM Mode

  • High Sensitivity: Detect even the weakest magnetic domains and structures
  • Excellent Spatial Resolution: Achieve lateral resolution down to 20 nm
  • Non-Destructive Imaging: Ideal for studying sensitive magnetic samples
  • Quantitative Measurements: Map relative strengths of magnetic fields across surfaces
  • Integration with Other Modes: Combine MFM with electrical or mechanical property mapping

Benefits of MFM Mode

  • Superior Resolution: Our advanced MFM implementation offers unparalleled spatial resolution and sensitivity.
  • User-Friendly Interface: Intuitive software makes MFM accessible to both experts and beginners.
  • Versatility: Easily combine MFM with other AFM modes for comprehensive sample characterization.
  • Cutting-Edge Research: Stay at the forefront of magnetic nanoscale characterization with our continuously updated technology.
Cobalt Alloy Coating topography and MFM results, Scan size 30µm x 30 µm
Cobalt Alloy Coating topography and MFM results,
Scan size 30µm x 30 µm
Cobalt Alloy Coating topography and MFM results, Scan size 30µm x 30 µm
Magnetical Pattern, Topography and MFM results
Scan size 24 µm x 24 µm
Stainless Steel, MFM Mode Scan size 18 µm x 18 µm​
Stainless Steel, MFM Mode
Scan size 18 µm x 18 µm
See alsoVariable Magnetic Field ModuleMore magnetic characterization features

How does MFM work?

MFM operates as a two-pass scanning technique:

  1. Topography Scan: A magnetically coated tip first scans the surface to record topography in tapping mode.
  2. Lift Mode: The tip is then raised to a specific height above the sample (typically 20-100 nm).
  3. Magnetic Force Detection: As the tip follows the topography at this constant height, it detects long-range magnetic forces.
  4. Data Recording: The system records the phase shifts of the cantilever oscillation, which correspond to the magnetic force gradient.

This two-pass technique allows for separate optimization of topographical and magnetic measurements, ensuring high-quality data for both.

how does the magnetic force microscopy mode work

Specifications

  • Lift Height Range: 10 nm – 200 nm
  • Lateral Resolution: < 20 nm (tip-dependent)
  • Compatible with all CSInstruments AFM systems
  • Optional: Variable magnetic field module for in-situ studies

Application Fields

Data Storage

  • Characterization of magnetic recording media
  • Analysis of bit patterns in hard drives
  • Development of next-generation magnetic storage technologies

Semiconductor Industry

  • Inspection of magnetic sensors and MEMS devices
  • Failure analysis in magnetic components

Materials Science

  • Study of magnetic domain structures in various materials
  • Investigation of magnetic thin films and multilayers
  • Characterization of novel magnetic nanomaterials

Spintronics

  • Research on spin-dependent transport phenomena
  • Development of spintronic devices

Geoscience

  • Analysis of magnetic properties in geological samples
  • Study of magnetic inclusions in minerals

Choosing an AFM for MFM

What makes a good AFM for magnetic force microscopy

MFM measures the long-range magnetic force gradient with a magnetic tip lifted above the surface. The quality of the image depends on the resolution, on keeping electrostatic forces out of the magnetic signal, and on being able to change the magnetic field while imaging. On the Nano-Observer AFMs from CSInstruments:

  • Resolution — lateral resolution below 20 nm (tip-dependent), lift height adjustable from 10 to 200 nm.
  • Pure magnetic contrast — EFC (electric field cancelling) removes the electrostatic tip–sample interaction, so the MFM image shows magnetism only.
  • Magnetic and electrical in one scan — MFM combined with HD-KFM™ surface potential on the same area.
  • Field-dependent imaging — the Variable Magnetic Field Module applies an in-plane or out-of-plane field (up to 3000 G in plane) during the scan, without current-induced sample heating, to follow domain switching.
  • Existing AFMs — MFM is kept when a MultiMode or Agilent AFM is upgraded with the Galaxy Dual Controller, which also adds HD-KFM™.

Variable Magnetic Field Module

MFM results

AFM scan of a permalloy device: MFM topography and magnetic signal, 20 µm
Permalloy deviceMFM · 20 µmPermalloy device · MFM · 1. Topography · 2. MFM signal (phase, lift mode) · Scan size: 20 microns
AFM scan of a permalloy device, closed view: MFM topography and magnetic signal, 4 µm
Permalloy device, closed viewMFM · 4 µmPermalloy device, closed view · MFM · 1. Topography · 2. MFM signal (phase, lift mode) · Scan size: 4 microns
AFM scan of a polymer with magnetic particles: MFM with EFC, topography and magnetic signal, 8 µm
Polymer with magnetic particlesMFM with EFC · 8 µmPolymer with magnetic particles · MFM with EFC · 1. Topography · 2. MFM signal (phase, lift mode) · Scan size: 8 microns
AFM scan of a thin magnetic coating on Si: topography and MFM signal while the out-of-plane field changes, 10 µm
Out-of-plane field variationMFM, out-of-plane field · 10 µmThin magnetic coating on Si · MFM with the out-of-plane field option · 1. Topography · 2. MFM signal, field changed during the scan: 300 gauss (upper half), 0 gauss (lower half) · Scan size: 10 microns
AFM scan of a thin magnetic coating on Si: topography and MFM signal while the in-plane field changes, 5 µm
In-plane field variationMFM, in-plane field · 5 µmThin magnetic coating on Si · MFM with the in-plane field option · 1. Topography · 2. MFM signal, field changed during the scan: 250 gauss (top), 125 gauss (middle), 0 gauss (bottom) · Scan size: 5 microns

Application note

MFM under an applied magnetic field

Domain rotation from 50 to 470 G and field steps within a single scan, in plane and out of plane: read the VMFM application note.

FAQ

Frequently Asked Questions

What is the best AFM for magnetic force microscopy (MFM)?

One that combines high resolution with control of the electrostatic and magnetic environment. The Nano-Observer AFMs reach below 20 nm lateral resolution in MFM (tip-dependent), cancel electrostatic forces with EFC, combine MFM with HD-KFM surface potential and can image under a variable magnetic field with the VMFM module.

How are electrostatic artefacts removed from MFM images?

With EFC (electric field cancelling): the electrostatic tip–sample interaction is cancelled during the MFM pass, so the image shows only the magnetic contrast.

Can magnetic domains be imaged while a magnetic field is applied?

Yes. The Variable Magnetic Field Module applies an in-plane or out-of-plane field (up to 3000 G in plane) during MFM imaging, without current-induced heating of the sample, so domain switching can be followed in situ.

Questions about MFM Mode?

Ask the application scientists behind our AFMs and modes — about your samples, probes, set-up or which mode fits your measurement. We answer every message personally.