High-energy-density permanent micromagnets formed from heterogeneous magnetic powder mixtures

Author

Oniku, O.D. ; Arnold, D.P.

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Florida, Gainesville, FL, USA

fYear

2012

fDate

Jan. 29 2012-Feb. 2 2012

Firstpage

436

Lastpage

439

Abstract

In this paper, we report the microfabrication and magnetic characterization of parylene-bonded permanent micromagnets. Mixtures of two different sized and shaped isotropic Nd-Fe-B powders are used to form 255 μm × 255 μm × 315 μm thick micromagnets embedded in silicon substrates. The best properties are obtained for a 50:50 mixture of the powders, yielding remanence B_r = 0.69 T, intrinsic coercivity H_ci = 680 kA/m, and energy product BH_max = 45 kJ/m³. Enabled by newly released commercially available magnetic powders, the results show a doubling in the energy density and remanence values over previously reported parylene-bonded magnets. The rapid, simple, low-temperature fabrication of these magnets, as well as their thermal and chemical stability, makes them attractive for magnetic MEMS applications.

Keywords

iron alloys; magnetic particles; micromechanical devices; neodymium alloys; permanent magnets; silicon; Nd-Fe-B; Si; chemical stability; energy density; heterogeneous magnetic powder mixtures; high-energy-density permanent micromagnets; intrinsic coercivity; isotropic powders; magnetic MEMS; parylene-bonded magnets; remanence values; size 255 mum; size 315 mum; thermal stability; Magnetic properties; Magnetic resonance imaging; Magnetomechanical effects; Perpendicular magnetic anisotropy; Powders; Remanence; Saturation magnetization;

fLanguage

English

Publisher

ieee

Conference_Titel

Micro Electro Mechanical Systems (MEMS), 2012 IEEE 25th International Conference on

Conference_Location

Paris

ISSN

1084-6999

Print_ISBN

978-1-4673-0324-8

Type

conf

DOI

10.1109/MEMSYS.2012.6170220

Filename

6170220