Skip to content
6CCVD Research

An overview of advanced instruments for magnetic characterization and measurements

At a Glance

Section titled “At a Glance”
MetadataDetails
Publication Date2025-09-01
JournalFrontiers in Electronics
AuthorsJunbiao Zhao, Lianhua Bai, Shen Li, Zhiqiang Cao, Yi‐Jen Peng
AnalysisFull AI Review Included

An Overview of Advanced Instruments for Magnetic Characterization and Measurements

Section titled “An Overview of Advanced Instruments for Magnetic Characterization and Measurements”

Executive Summary

Section titled “Executive Summary”

This review provides a systematic analysis of advanced magnetic measurement techniques, categorized into static, dynamic, and emerging spintronic methods, crucial for material innovation and device engineering.

  • Comprehensive Toolkit: The paper details the working principles and structures of foundational static magnetometers (VSM, AGM, SQUID) and dynamic methods (AC Susceptometry, FMR) for macroscopic property analysis.
  • High Sensitivity and Precision: Techniques like AGM (10-8 emu) and SQUID (10-8 emu) are highlighted for characterizing ultra-weak magnetic signals, essential for micro- and nano-electronic materials.
  • Nanoscale Imaging: High-resolution tools, including MFM, MOKE, SP-STM (atomic-scale), and LTEM (2-20 nm resolution), are detailed for visualizing magnetic domain structures and topological spin textures (e.g., skyrmions).
  • Dynamic and Ultrafast Analysis: FMR and AC Susceptometry are critical for probing frequency-dependent behavior, spin relaxation, and quantifying Gilbert damping constants, with TR-MOKE achieving sub-picosecond temporal resolution.
  • Spintronic Relevance: Emerging quantum techniques, such as NV-center magnetometry and Soft X-ray methods (XMCD/XMLD), offer non-invasive, element-specific, and spin-sensitive analysis required for next-generation spintronic devices.
  • Future Trajectories: Development is focused on integrating AI for data analysis, multi-field coupling platforms, and high-field/cryogenic systems (up to 100 T) to advance quantum magnetism research.

Technical Specifications

Section titled “Technical Specifications”
ParameterValueUnitContext
VSM Sensitivity (Typical)10-7 to 10-8emuStatic magnetic moment resolution.
AGM Sensitivity (Typical)10-8emuStatic magnetic moment resolution.
AGM Noise Floor (Lowest Reported)10-12emuAchieved using quartz tuning fork sensor.
SQUID Sensitivity10-8emuUltra-high precision magnetic moment detection.
SQUID Operating Temperature1.8KUltra-low temperature environment required.
MOKE Spatial Resolution~300nmMagnetic domain imaging capability.
TR-MOKE Temporal ResolutionSub-picosecondN/AUltrafast magnetization dynamics studies.
FMR Frequency Range (Broadband)Up to 65GHzPlanar transmission line setups (VNA-FMR).
LTEM Spatial Resolution2-20nmHigh-resolution magnetic domain imaging.
SP-STM Spatial ResolutionAtomic-scaleN/ALocal spin polarization imaging.
High Magnetic Field (Hybrid)45TStable, user-accessible hybrid magnet systems.
High Magnetic Field (Pulsed)Up to 100TUsed for probing exotic magnetic phases.

Key Methodologies

Section titled “Key Methodologies”

The following outlines the core principles and operational modes of the primary magnetic characterization instruments:

  1. Vibrating Sample Magnetometer (VSM):
    • Principle: Electromagnetic Induction. A magnetized sample is mechanically vibrated within a uniform DC field, inducing an AC voltage (Vemf) in stationary pickup coils, proportional to the sample’s magnetic moment.
    • Structure: Uses an electromagnet for DC field, a mechanical oscillator for sinusoidal vibration (tens of Hz), and a lock-in amplifier (LIA) for signal extraction.
  2. Alternating Gradient Magnetometer (AGM):
    • Principle: Magnetic Force Balance. The sample is subjected to an alternating magnetic field gradient, causing vibration. The resulting force is detected by a piezoelectric bimorph or laser vibrometer.
    • Detection: Measures the force (F) proportional to the magnetic moment (m) and the field gradient (dH/dx).
  3. Superconducting Quantum Interference Device (SQUID) Magnetometer:
    • Principle: Josephson Effect and Flux Quantization. Converts extremely small changes in magnetic flux (Ί) into measurable voltage signals using Josephson junctions embedded in a superconducting loop.
    • Modes: DC scan (sample translated through gradiometer) or SQUID-VSM (sample vibrated at fixed frequency). Utilizes a flux-locked loop (FLL) for linearity and ultra-high sensitivity.
  4. Magneto-Optical Kerr Microscope (MOKE):
    • Principle: Magneto-Optical Kerr Effect. Detects changes in the polarization state (rotation and ellipticity) of reflected polarized light due to sample magnetization.
    • Application: Real-time, surface-sensitive imaging of magnetic domains and domain wall dynamics.
  5. Magnetic Force Microscope (MFM):
    • Principle: Dipolar Interaction. Maps the magnetic stray field distribution by measuring the force gradient between a ferromagnetic tip and the sample surface using a scanning cantilever.
    • Application: Nanoscale imaging of domain structures and current-induced domain wall motion.
  6. Ferromagnetic Resonance (FMR)-based System:
    • Principle: Resonant Absorption. Measures the resonant precession of the magnetization vector (m) induced by a combination of a static magnetic field (HDC) and a microwave oscillating field (HRF).
    • Methods: Cavity-FMR (high sensitivity, fixed frequency) or VNA-FMR (broadband frequency coverage) for quantifying damping and anisotropy.
  7. Emerging Spintronic Techniques:
    • NV-Center Magnetometry: Uses the Zeeman splitting of negatively charged nitrogen-vacancy spin states in diamond, read out optically, for nanoscale, non-invasive magnetic field detection.
    • Spin-Polarized Scanning Tunneling Microscope (SP-STM): Relies on the spin dependence of the tunneling current between a spin-polarized tip and sample for atomic-scale imaging of spin textures.
    • Soft X-ray Techniques (XMCD/XMLD): Utilizes element- and spin-sensitive X-ray absorption spectroscopy (often combined with PEEM) to image magnetization in thin films and multilayers.

Commercial Applications

Section titled “Commercial Applications”

The advanced magnetic characterization techniques reviewed are essential across several high-technology sectors:

  • Spintronic Device Development:
    • Optimization and quality control of Magnetic Random Access Memory (MRAM) and spin-transfer torque (STT) devices.
    • Characterization of materials for racetrack memory and all-optical switching (AOS) technologies.
  • Information Storage and Recording:
    • Analysis of stray magnetic fields generated by recording heads (MFM).
    • Investigation of written domains in magneto-optical storage films and longitudinal magnetic media.
  • Quantum Technology and Sensing:
    • Development of scalable, low-power, CMOS-compatible on-chip magnetometers (NV-center, miniaturized SQUID).
    • Biomedical diagnostics and microscale magnetic imaging using quantum magnetic sensors.
  • Fundamental Materials Research:
    • Probing magnetic phase transitions (Curie/NĂ©el temperature) and superconducting properties (AC Susceptometry, SQUID).
    • Investigation of topological magnetic textures (skyrmions, spin spirals) in novel quantum materials (SP-STM, LTEM).
  • Advanced Instrumentation:
    • Integration of AI algorithms for real-time data analysis and intelligent interpretation of complex magnetic textures.
    • Engineering of high-field (up to 100 T) and cryogenic measurement platforms for exotic magnetic phases.
View Original Abstract

Magnetic materials play a pivotal role in emerging fields such as new energy, information technology, and biomedicine, where accurate magnetic characterization is essential for material innovation and device engineering. Notably, with the burgeoning development of nanomaterials and spintronics, the importance of magnetic characterization has grown significantly, accompanied by increasingly higher requirements for precision and multi-dimensional analysis. This paper elaborates on the working principles and structural components of static magnetic measurement techniques—including Vibrating Sample Magnetometer (VSM), Alternating Gradient Magnetometer (AGM), Magneto-Optical Kerr Effect (MOKE) Microscope, Magnetic Force Microscope (MFM) and Superconducting Quantum Interference Device (SQUID) Magnetometer, as well as dynamic magnetic measurement techniques such as Alternating Current (AC) susceptometry and Ferromagnetic Resonance (FMR). In addition, this review also introduces emerging techniques relevant to spintronics, including Magnetometer based on negatively charged nitrogen-vacancy (NV − ) centers in diamond, Spin-polarized Scanning Tunneling Microscope (SP-STM), Lorentz Transmission Electron Microscope (LTEM), and Soft X-ray-based techniques, highlighting their principles and applications in quantum sensing, magnetic imaging, and element-specific spin analysis. This overview emphasizes the unique capabilities and measurement principles of each magnetic characterization instrument, providing users with practical guidance to identify the most appropriate tool based on specific research objectives, material properties, and experimental requirements, thereby improving characterization efficiency and accuracy.

Tech Support

Section titled “Tech Support”

Original Source

Section titled “Original Source”

References

Section titled “References”
  1. 2009 - Single Pt/Co (0.5 nm)/Pt nano-discs: beyond the coherent spin reversal model and thermal stability [Crossref]
  2. 2010 - Magnetization reversal in Pt/Co (0.5 nm)/Pt nano-platelets patterned by focused ion beamlithography [Crossref]
  3. 2024 - Magnetic domain and structural defects size in ultrathin films [Crossref]
  4. 2023 - Development of magnetic nanoparticle based nanoabrasives for magnetorheological finishing process and all their variants [Crossref]
  5. 2021 - Room temperature ferromagnetic behavior of nickel-doped zinc oxide dilute magnetic semiconductor for spintronics applications [Crossref]
  6. 1955 - Theory of the Faraday and Kerr effects in ferromagnetics [Crossref]
  7. 2024 - Spin-polarized scanning tunneling microscopy measurements of an Anderson impurity [Crossref]
  8. 2013 - AC susceptibility studies of phase transitions and magnetic relaxation: conventional, molecular and low-dimensional magnets [Crossref]
  9. 2004 - Sensitive measurement of reversible parallel and transverse susceptibility by alternating gradient magnetometry [Crossref]
  10. 2020 - Sensitivity optimization for NV- diamond magnetometry [Crossref]

Reads Similar to This

Engineering defect clustering in diamond-based materials for technological applications via quantum mechanical descriptors Fabrication of Boron-Doped Diamond Film Electrode for Detecting Trace Lead Content in Drinking Water A Vector-total Field Magnetometry and Calibration Using NV Center Ensembles