Abstract
We have recently studied the effects of a magnetic field (H̄) applied normal to an initially established remanent magnetization (MR). Pertinent to this, we have extended the Stoner-Wohlfarth model for a ferromagnetic aggregate of single-domain particles with randomly oriented anisotropies of the same strength. The extended model predicts that MT, the magnetization transverse to H̄, stays close to MR until H reaches a critical value, and then drops rapidly to zero at higher H. Deviations from this sharp behavior can be readily interpreted in terms of a spread in the size of the particle anisotropies. Thus, from experimental data for a commercial magnetic-memory material, we have deduced that the anisotropy spread is nonzero but fairly narrow. We also considered this property for a type-II superconductor, where MR consists of parallel vortices pinned by sample imperfections. If the pinning of every vortex were identical in strength, MT can be again expected to stay constant at MR up to a critical value of H and then decrease rapidly. Instead, our experimental data for polycrystalline YBCO at 4.2K show MT decreasing steadily as H rises from zero, indicative of a very broad distribution in the strength of the vortex pinning.
Original language | English |
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Pages (from-to) | 234-240 |
Number of pages | 7 |
Journal | Physica B: Condensed Matter |
Volume | 321 |
Issue number | 1-4 |
DOIs | |
Publication status | Published - Aug 2002 |
Externally published | Yes |
Event | Proceedings of the Second Regional Conference on Magnetic and (MSS-01) - Irbid, Jordan Duration: Sept 9 2001 → Sept 13 2001 |
Keywords
- Ferromagnetic particles
- Transverse field effects
- Type-II superconductor
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering