Thermomagnetic fluctuations and hysteresis loops of magnetic cantilevers for magnetic resonance force microscopy

• Published in: IEEE transactions on magnetics Vol. 42; no. 3; pp. 378 - 381
• Main Authors: Tse Nga Ng, Jenkins, N.E., Marohn, J.A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Cantilever magnetometry; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fluctuation; Fluctuations; Hysteresis; Hysteresis loops; Magnetic anisotropy; Magnetic fields; magnetic fluctuations; Magnetic force microscopy; magnetic force resonance microscopy; Magnetic hysteresis; Magnetic resonance; Magnetism; Magnets; Materials science; Microscopy; Nickel; Other topics in materials science; Perpendicular magnetic anisotropy; Physics; Thermal force; Cantilever magnetometry; magnetic force resonance microscopy; Magnetic domains; Magnetic resonance; Magnetic loop; magnetic fluctuations; Magnetic hysteresis; Magnetic materials; Magnetic properties
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2006.870259

We have used frequency-shift cantilever magnetometry to study individual nickel magnets patterned at the end of ultra-sensitive silicon cantilevers for use in magnetic resonance force microscopy (MRFM). We present a procedure for inferring a magnet's full hysteresis curve from the response of cantilever resonance frequency versus magnetic field. Hysteresis loops and small-angle fluctuations were determined at 4.2 K with an applied magnetic field up to 6 T for magnets covering a range of dimensions and aspect ratios. Compared to magnetic materials with higher anisotropy, we find that nickel is preferable for MRFM experiments on nuclear spins at high magnetic fields.