Origin of magnetization decay in spin-dependent tunnel junctions

Science

Volumn 286, Issue 5443, 1999, Pages 1337-1340

  McCartney, Martha R ^a   Dunin Borkowski, Rafal E ^a   Scheinfein, Michael R ^a   Smith, David J ^a   Gider, Savas ^a   Parkin, Stuart S P ^a  

^a NONE

Author keywords

[No Author keywords available]

Indexed keywords

ANISOTROPY; ARTICLE; MAGNETIC FIELD; MAGNETIC STIMULATION; MAGNETISM; PRIORITY JOURNAL; STRENGTH;

EID: 0032723883     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.286.5443.1337     Document Type: Article

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12. The magnetic microstructure was studied with a Philips CM200ST-FEC transmission electron microscope, equipped with a minilens for magnetic imaging, and a slow-scan charge-coupled device camera. The immersion objective lens provided a vertical field at the specimen of 825 Oe. The sample was repeatedly tilted by ±14° with an automated goniometer to reverse the soft-layer magnetization, using the in-plane magnetic field of ±200 Oe (the hard CoPtCr film had been saturated by applying a 10-kOe in-plane field). Lorentz images were recorded at the sample tilt corresponding to -200 Oe when the soft FM layer was saturated and the remaining image contrast was due to residual magnetization ripple in the CoPtCr hard layer. AU Lorentz images were recorded under identical conditions and were carefully aligned so that changes in contrast could be related to microstructural and micromagnetic features. Using image subtraction, contrast changes could be monitored, allowing the nucleation and growth of magnetic domains within the hard layer to be identified.
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15. Partly supported by funding from the Advanced MRAM Project of the Defense Advanced Research Projects Agency. We acknowledge the use of facilities at the Center for High Resolution Electron Microscopy at Arizona State University. M.R.S. and S.S.P.P. thank P. Trouilloud of the IBM T.J. Watson Research Center for discussions that contributed substantially to this work, and we thank J. Speidell for supplying silicon nitride membranes.