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Christian Binek Publications

2003

Articles 1 - 2 of 2

Full-Text Articles in Physics

Giant Metamagnetic Moments In A Granular Fecl2-Fe Heterostructure, Sarbeswar Sahoo, Christian Binek, Wolfgang Kleemann Nov 2003

Giant Metamagnetic Moments In A Granular Fecl2-Fe Heterostructure, Sarbeswar Sahoo, Christian Binek, Wolfgang Kleemann

Christian Binek Publications

Giant moments are observed at low temperatures in a granular FeCl2-Fe heterostructure owing to a local metamagnetic transformation of the antiferromagnetic (AF) FeCl2 matrix due to dipolar interactions. A model of metamagnetically (MM) "dressed" single-domain Fe particles is suggested to explain the observations. These include polydispersive ac susceptibility induced by AF-MM domain configurations and weak exchange bias due to non-spin-flipped AF crystallites.


Cole-Cole Analysis Of The Superspin Glass System Co80Fe20/Al2O3, O. Petracic, Sarbeswar Sahoo, Christian Binek, Wolfgang Kleemann, J.B. Sousa, Susana Cardoso De Freitas, P.P. Freitas Apr 2003

Cole-Cole Analysis Of The Superspin Glass System Co80Fe20/Al2O3, O. Petracic, Sarbeswar Sahoo, Christian Binek, Wolfgang Kleemann, J.B. Sousa, Susana Cardoso De Freitas, P.P. Freitas

Christian Binek Publications

Ac susceptibility measurements were performed on discontinuous magnetic multi-layers [Co80Fe20 (t)/Al2O3 (3 nm)] 10, t = 0.9 and 1.0 nm, by Superconducting Quantum Interference Device (SQUID) magnetometry. The CoFe forms nearly spherical ferromagnetic single-domain nanoparticles in the diamagnetic Al2O3 matrix. Due to dipolar interactions and random distribution of anisotropy axes the system exhibits a spin-glass phase. We measured the ac susceptibility as a function of temperature 20 ≤ T ≤ 100 K at different dc fi elds and as a function of frequency 0.01 ≤ f ≤ 1000 Hz. The spectral data ...