Analysing Magnetism Using Scanning SQUID Microscopy

Abstract

Scanning superconducting quantum interference device microscopy (SSM) is a scanning probe technique that images local magnetic flux, which allows for mapping of magnetic fields with high field and spatial accuracy. Many studies involving SSM have been published in the last decades, using SSM to make qualitative statements about magnetism. However, quantitative analysis using SSM has received less attention. In this work, we discuss several aspects of interpreting SSM images and methods to improve quantitative analysis. First, we analyse the spatial resolution and how it depends on several factors. Second, we discuss the analysis of SSM scans and the information obtained from the SSM data. Using simulations, we show how signals evolve as a function of changing scan height, SQUID loop size, magnetization strength and orientation. We also investigated 2-dimensional autocorrelation analysis to extract information about the size, shape and symmetry of magnetic features. Finally, we provide an outlook on possible future applications and improvements.

16 pages, 10 figures

References in corpus (11)

• Direct imaging of the coexistence of ferromagnetism and superconductivity at the LaAlO3/SrTiO3 interface
• Inhomogeneity of charge density wave order and quenched disorder in a high Tc superconductor
• Imaging currents in HgTe quantum wells in the quantum spin Hall regime
• Self-aligned nanoscale SQUID on a tip
• Evidence for Nodal Superconductivity in LaFePO from Scanning SQUID Susceptometry
• Scanning SQUID susceptometers with sub-micron spatial resolution
• Vortex trapping and expulsion in thin-film YBCO strips
• Emergent nanoscale superparamagnetism at oxide interfaces
• A Terraced Scanning Superconducting Quantum Interference Device Susceptometer with Sub-Micron Pickup Loops
• Limits on the Superconducting Order Parameter in NdFeAsO${}_{1-x}$F${}_y$ from Scanning SQUID Microscopy
• Spatially resolved penetration depth measurements and vortex manipulation in the ferromagnetic superconductor ErNi2B2C

Cited by in corpus (6)

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• Structure and magnetic properties of epitaxial CaFe2O4 thin films
• Direct observation of quantum anomalous vortex in Fe(Se,Te)
• Magnetic imaging and statistical analysis of the metamagnetic phase transition of FeRh with electron spins in diamond
• Measurements of the magnetic properties of conduction electrons
• Imaging the suppression of ferromagnetism in LaMnO${}_3$ by metallic overlayers