Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Magnetismus
MA 20: Poster: Films(1-36) Transp(37-56) Ex.Bias(57-67) Spindyn(68-80) Micromag(81-95) Particle(96-109) Imag.+Surface(110-113) Spinelectr(114-122) Theory+Micromag(123-131) Spinstr+Aniso(132-142) MagMat(143-156) Meas(157,158) MolMag+Kondo(159-162) Postdead(163-)
MA 20.20: Poster
Dienstag, 28. März 2006, 15:15–19:15, P1
Magnetotransport in CrO2 single ferromagnetic domains — •S.W. Schink1, S.T.B. Goennenwein1, M. Opel1, R. Gross1, R.S. Keizer2, T.M. Klapwijk2, G. Miao3,4, G. Xiao4, and A. Gupta3 — 1Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching, Germany — 2Kavli Institute of NanoScience, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands — 3MINT Center, University of Alabama, Tuscaloosa, AL, USA — 4Physics Department, Brown University, Providence, RI, USA
Ferromagnetic materials with high spin polarisation (P) are very attractive for spin electronics. Chromium dioxide (CrO2) is a well established half-metallic ferromagnet with a Curie temperature TC ≈ 390 K and P ≈ 0.98. We have investigated the magnetic anisotropy of 150 nm thick CrO2 single crystal films using magnetotransport measurements. The films were patterned into Hall-bar mesa structures with optical lithography and etching. The anisotropic magnetoresistance (AMR) was then measured with the external magnetic field applied in the film plane. We observe clear steps in both the longitudinal (sheet) and the transverse (planar Hall) magnetoresistance. This shows that the AMR is determined by one single, macroscopic magnetic domain, which abruptly switches from one easy axis to another. Our experiments thus are clear evidence that the CrO2 thin films exhibit a biaxial magnetic anisotropy in the film plane. We discuss the influence of temperature, crystalline strain and specimen shape on the in-plane magnetic anisotropy.