Thermomagnetic switching in amorphous rare-earth transition metal alloys

Journal Article · Wed Jul 01 04:00:00 EDT 1987 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.339185· OSTI ID:6544885

Hansen, P

Conditions for writing and erasure have been investigated for different amorphous rare-earth transition metal alloys using a simple temperature distribution evaluated for a three-layer structure. The radial and time dependence of the magnetic parameters relevant for the switching process have been calculated by means of the mean-field theory based on experimental data of the saturation magnetization, uniaxial anisotropy, and the coercivity, for alloys of composition (Gd,Tb)/sub 1-//sub x/Fe/sub x/ and Tb/sub 1-//sub x/(Fe,Co)/sub x/. From the radial profiles of the coercive field, maximum domain diameters are extracted in the limit of large domain velocities. Domain-wall stabilities are calculated from the force equation for writing and erasure conditions as a function of applied field yielding margins for stable domains and collapse fields. In addition to bubblelike domains, ring domain configurations are considered, which imply the possibility of direct overwrite for alloys with a compensation temperature above ambient temperature. The switching with a continuous read power level is discussed.

• Research Organization: Philips GmbH Forschungslaboratorium Hamburg, D-2000 Hamburg 54, Vogt-Koelln-Strasse 30, Federal Republic of Germany
• OSTI ID: 6544885
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 62:1; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
ANISOTROPY
COBALT ALLOYS
COERCIVE FORCE
DOMAIN STRUCTURE
GADOLINIUM ALLOYS
IRON ALLOYS
LAYERS
MAGNETIC DISKS
MAGNETIC PROPERTIES
MAGNETIC STORAGE DEVICES
MAGNETISM
MAGNETIZATION
MAGNETO-OPTICAL EFFECTS
MATERIALS
MEMORY DEVICES
PHYSICAL PROPERTIES
RARE EARTH ALLOYS
TERBIUM ALLOYS
THERMOMAGNETISM