Title :
Sputtered sandwich heads for high-density digital video recording
Author :
Dirne, F.W.A. ; Ruigrok, J.J.M.
Author_Institution :
Philips Res. Lab., Eindhoven, Netherlands
fDate :
9/1/1990 12:00:00 AM
Abstract :
A sandwich type of head for application in high-frequency and high-density digital video systems is described. Amorphous CoNbZr films laminated with an Al2O3 insulator layer are used as core material. The influence of rotating and static field annealing on the domain structure and on the permeability is discussed. In order to achieve a sufficiently high efficiency, a polycrystalline ferrite back yoke is applied. Sandwich heads with several ceramic materials in the contact plane are evaluated. The performance of the heads is investigated on the basis of a signal-to-noise criterion, defined specially for the digital video application. A sandwich head made with 2 μm×5 μm amorphous CoNbZr, laminated with 0.1 μm Al2 O3, between glass-ceramic substrates fulfils the requirement on MP tape
Keywords :
alumina; cobalt alloys; laminates; magnetic cores; magnetic domains; magnetic heads; magnetic permeability; magnetic recording; magnetic thin film devices; niobium alloys; sputtered coatings; video recording; video tape recorders; zirconium alloys; 0.1 micron; 2 micron; 5 micron; CoNbZr-Al2O3; amorphous films; ceramic materials; contact plane; core material; domain structure; glass-ceramic substrates; high-density digital video recording; insulator layer; performance; permeability; polycrystalline ferrite back yoke; signal-to-noise criterion; sputtered sandwich heads; static field annealing; Amorphous materials; Annealing; Ferrite films; Frequency; Magnetic heads; Magnetic materials; Magnetostriction; Permeability; Substrates; Video recording;
Journal_Title :
Magnetics, IEEE Transactions on
