title: Quantitative magnetic force microscopy on permalloy dots using an iron filled carbon nanotube probe.
abstract: An iron filled carbon nanotube (FeCNT), a 10-40 nm ferromagnetic nanowire enclosed in a protective carbon tube, is an attractive candidate for a magnetic force microscopy (MFM) probe as it provides a mechanically and chemically robust, nanoscale probe. We demonstrate the probe's capabilities with images of the magnetic field gradients close to the surface of a Py dot in both the multi-domain and vortex states. We show the FeCNT probe is accurately described by a single magnetic monopole located at its tip. Its effective magnetic charge is determined by the diameter of the iron wire and its saturation magnetization 4πM(s) ≈ 2.2 × 10(4)G. A magnetic monopole probe is advantageous as it enables quantitative measurements of the magnetic field gradient close to the sample surface. The lateral resolution is defined by the diameter of the iron wire and the probe-sample separation.
authors.affiliation: Leibniz Institute for Solid State and Materials Research (IFW), Dresden, Helmholtzstr. 20, 01069 Dresden, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Wolny
authors.forename: Y
authors.initials: Y
authors.lastname: Obukhov
authors.forename: T
authors.initials: T
authors.lastname: Mühl
authors.forename: U
authors.initials: U
authors.lastname: Weissker
authors.forename: S
authors.initials: S
authors.lastname: Philippi
authors.forename: A
authors.initials: A
authors.lastname: Leonhardt
authors.forename: P
authors.initials: P
authors.lastname: Banerjee
authors.forename: A
authors.initials: A
authors.lastname: Reed
authors.forename: G
authors.initials: G
authors.lastname: Xiang
authors.forename: R
authors.initials: R
authors.lastname: Adur
authors.forename: I
authors.initials: I
authors.lastname: Lee
authors.forename: A J
authors.initials: AJ
authors.lastname: Hauser
authors.forename: F Y
authors.initials: FY
authors.lastname: Yang
authors.forename: D V
authors.initials: DV
authors.lastname: Pelekhov
authors.forename: B
authors.initials: B
authors.lastname: Büchner
authors.forename: P C
authors.initials: PC
authors.lastname: Hammel