Dynamic writing of magnetic domains in GdTbFe: Observations made by Lorentz microscopy

Journal Article · Wed Nov 15 04:00:00 EST 1989 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.343761· OSTI ID:5373993

Greidanus, F J.A.M.; Jacobs, B A.J.; den Broeder, F J.A.; Spruit, J H.M. ^[1]; Rosenkranz, M ^[2]

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1. Philips Research Laboratories, P.O. Box 80.000, 5600 JA, Eindhoven, The Netherlands (NL)
2. Philips GmbH Forschungslaboratorium Hamburg, D-2000 Hamburg, Federal Republic of Germany (DE)

In this paper the sizes and shapes of thermally written magnetic domains in a GdTbFe layer are discussed. The magneto-optical layer is deposited on a specially prepared silicon wafer disk, provided with Si{sub 3}N{sub 4} windows. This allows dynamic writing of domains under realistic recording conditions on a rotating substrate and direct observation of the magnetization patterns in the transmission electron microscope, using Lorentz microscopy. Domain patterns were written in two different ways: With the first method, laser modulation (LM), the laser beam was modulated while applying a fixed field. In the second method, magnetic field modulation (MFM), the laser was on continuously and the applied magnetic field was modulated. With LM it was observed that both size and shape are closely dependent on the magnitude of the applied field. This behavior is in good agreement with observations made with optical readout of similar magneto-optical disks. Domains written with MFM have somewhat irregular contours. The degree of irregularity depends on the magnitude of the applied magnetic field and its switching time. Reduction of these irregularities can be achieved by simultaneously modulating the laser beam.

• OSTI ID: 5373993
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 66:10; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
DOMAIN STRUCTURE
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
ELEMENTS
GADOLINIUM ALLOYS
IRON ALLOYS
LASER RADIATION
LAYERS
MAGNETIC STORAGE DEVICES
MAGNETO-OPTICAL EFFECTS
MEMORY DEVICES
MICROSCOPY
NITRIDES
NITROGEN COMPOUNDS
PNICTIDES
RADIATIONS
RARE EARTH ALLOYS
SEMIMETALS
SILICON
SILICON COMPOUNDS
SILICON NITRIDES
SUBSTRATES
TERBIUM ALLOYS
TRANSMISSION ELECTRON MICROSCOPY