Title :
Evaporatively deposited Co-MgF2 granular materials for thin-film inductors
Author :
Coonley, Kip D. ; Mehas, Gustavo J. ; Sullivan, Charles R. ; Gibson, Ursula J.
Author_Institution :
Thayer Sch. of Eng., Dartmouth Coll., Hanover, NH, USA
fDate :
9/1/2000 12:00:00 AM
Abstract :
Co-MgF2 granular thin films prepared by thermal evaporation are reported. The fabricated materials show promise as high-frequency, low-loss cores for microfabricated magnetic devices in microprocessor power delivery applications. Transmission electron microscopy (TEM) reveals Co grains of about 3.2 nm embedded in a MgF2 matrix 1 to 2 nm wide. Films were prepared with 20% to 89% volume cobalt at substrate temperatures between -21°C and 311°C. Good soft magnetic properties in a range of 40% to 55% volume cobalt with high DC resistivity of 500 μΩ-cm to 100 Ω-cm are measured for films deposited at room temperature. Low intrinsic coercivity, Hci of 0.76 Oe and susceptibility, χ of 26 in the easy axis direction with quality factor, Q over 100 and saturation flux density, Bs of 0.7 T are obtained
Keywords :
Q-factor; cobalt; coercive force; computer power supplies; electrical resistivity; granular materials; magnesium compounds; magnetic cores; magnetic susceptibility; magnetic thin films; microcomputers; power inductors; soft magnetic materials; transmission electron microscopy; vacuum deposited coatings; vacuum deposition; -21 to 311 C; 0.7 T; Co-MgF2; TEM; easy axis direction; evaporatively deposited granular materials; granular thin films; high DC resistivity; high-frequency low-loss cores; intrinsic coercivity; microfabricated magnetic devices; microprocessor power delivery applications; quality factor; room temperature; saturation flux density; soft magnetic properties; susceptibility; thermal evaporation; thin-film inductors; transmission electron microscopy; Cobalt; Magnetic cores; Magnetic devices; Magnetic films; Magnetic materials; Magnetic properties; Microprocessors; Temperature; Transistors; Transmission electron microscopy;
Journal_Title :
Magnetics, IEEE Transactions on
