title: Ultrasoft magnetic films investigated with Lorentz tranmission electron microscopy and electron holography.
abstract: As a tribute to the scientific work of Professor Gareth Thomas in the field of structure-property relationships this paper delineates a new possibility of Lorentz transmission electron microscopy (LTEM) to study the magnetic properties of soft magnetic films. We show that in contrast to the traditional point of view, not only does the direction of the magnetization vector in nano-crystalline films make a correlated small-angle wiggling, but also the magnitude of the magnetization modulus fluctuates. This fluctuation produces a rapid modulation in the LTEM image. A novel analysis of the ripple structure in nano-crystalline Fe-Zr-N film corresponds to an amplitude of the transversal component of the magnetization deltaMy of 23 mT and a longitudinal fluctuation of the magnetization of the order of deltaMx = 30 mT. The nano-crystalline (Fe99Zr1)1-xNx films have been prepared by DC magnetron reactive sputtering with a thickness between 50 and 1000 nm. The grain size decreased monotonically with N content from typically 100 nm in the case of N-free films to less than 10 nm for films containing 8 at%. The specimens were examined with a JEOL 2010F 200 kV transmission electron microscope equipped with a post column energy filter (GIF 2000 Gatan Imaging Filter). For holography, the microscope is mounted with a biprism (JEOL biprism with a 0.6 microm diameter platinum wire).
authors.affiliation: Department of Applied Physics, Materials Science Center and Netherlands Institute for Metals Research, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Jeff Th M
authors.initials: JT
authors.lastname: De Hosson
authors.forename: Nicolai G
authors.initials: NG
authors.lastname: Chechenin
authors.forename: Daan-Hein
authors.initials: DH
authors.lastname: Alsem
authors.forename: Tomas
authors.initials: T
authors.lastname: Vystavel
authors.forename: Bart J
authors.initials: BJ
authors.lastname: Kooi
authors.forename: Antoni R
authors.initials: AR
authors.lastname: Chezan
authors.forename: Dik O
authors.initials: DO
authors.lastname: Boerma
mesh_terms: D000497:Alloys / Q000032:analysis; D006696:Holography / Q000379:methods*; D007501:Iron / Q000032:analysis*; D008280:Magnetics; D008854:Microscopy, Electron / Q000295:instrumentation / Q000379:methods; D009584:Nitrogen / Q000032:analysis*; D015040:Zirconium / Q000032:analysis*
chemical_list: D000497:Alloys; D015040:Zirconium; D007501:Iron; D009584:Nitrogen