Title :
Influence of particle size distribution in cermet nanocomposites on magnetoresistance sensitivity
Author :
O´Connor, C.J. ; Golub, V.O. ; Vovk, A.Ya. ; Kraets, A.F. ; Pogoriliy, A.M.
Author_Institution :
AMRI, New Orleans Univ., LA, USA
fDate :
9/1/2002 12:00:00 AM
Abstract :
Tunneling magnetoresistance (TMR) and magnetic properties of (Co50Fe50)x-(Al2O3)1-x granular films prepared by dual electron beam evaporation were studied. The influence of the particle size distribution (PSD) on magneto-transport properties is reported. It was found that TMR versus M behavior does not follow (M/Ms)2 law (M and Ms are magnetization and saturation magnetization, respectively), predicted for uniform size spherical particles with uncorrelated magnetic moments. Deviation from quadratic law is determined by PSD and is maximal for the films with the broadest distribution of superparamagnetic particles. For these films, the highest values of TMR and field sensitivity were also observed. The effect of PSD could be used for enhancement of TMR sensitivity in granular nanocomposites.
Keywords :
alumina; cermets; cobalt alloys; discontinuous metallic thin films; giant magnetoresistance; iron alloys; magnetic hysteresis; magnetic particles; magnetic susceptibility; magnetic thin films; nanostructured materials; particle size; percolation; superparamagnetism; tunnelling; CoFe-Al2O3; cermet nanocomposites; dual electron beam evaporation; granular films; granular nanocomposites; hysteresis loops; magnetic clusters; magnetic nanoparticles; magnetic properties; magnetic susceptibility; magnetoresistance sensitivity; particle size distribution; percolation cluster; quadratic law deviation; saturation magnetization; superparamagnetic particles; tunneling magnetoresistance; Ceramics; Electron beams; Insulation; Iron; Magnetic films; Magnetic materials; Magnetic properties; Nanocomposites; Saturation magnetization; Tunneling magnetoresistance;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2002.801967
