Bimodal magnetic force microscopy with capacitive tip-sample distance control

• Published in: Applied physics letters Vol. 107; no. 13
• Main Authors: Schwenk, J., Zhao, X., Bacani, M., Marioni, M. A., Romer, S., Hug, H. J.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 28-09-2015
• Subjects: Applied physics; Magnetic fields; Magnetic force microscopy; Microscopy; Phase locked loops; Q factors; Topography
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4932174

A single-passage, bimodal magnetic force microscopy technique optimized for scanning samples with arbitrary topography is discussed. A double phase-locked loop system is used to mechanically excite a high quality factor cantilever under vacuum conditions on its first mode and via an oscillatory tip-sample potential on its second mode. The obtained second mode oscillation amplitude is then used as a proxy for the tip-sample distance, and for the control thereof. With appropriate z-feedback parameters, two data sets reflecting the magnetic tip-sample interaction and the sample topography are simultaneously obtained.