Effect of interaction in the magnetization reversal relaxation of superparamagnetic granulaR CoFeB -SiO2 FILMS
2009 (English)In: Magnetism and Magnetic Materials, Scientific.Net , 2009, 213-216 p.Conference paper (Refereed)
In order to study the magnetic interactions influence on the relaxation processes in superparamagnetic media, the magnetostatic measurements were carried out for the granular (CoFeB)x-(SiO2)1-x films with x values near percolation threshold. The observed temperature dependences of the coercivity for the samples magnetized along in-plane easy axis have shown two parts linear on √T with different inclination angles, which cross each other at the blocking temperature (Tb). The first part of the curve, which corresponds to the temperature range below T b, depends on the measuring time and is related to the thermal activation nature of magnetization reversal process in the blocked superparamagnetic state. Second part of the curve, which corresponds to the temperature range above Tb, is practically independent on the measuring time and is related to existence of correlated state of superparamagnetic grains moments, i.e. to superferromagnetic state. The method of the magnetization reversal curves simulation based on the numerical solving of kinetic equation has been applied to explain the experimental results.
Place, publisher, year, edition, pages
Scientific.Net , 2009. 213-216 p.
, Solid State Phenomena, ISSN 1012-0394 ; 152-153
Measuring time, Nanogranular ferromagnetic films, Superparamagnetic state, Blocking temperature, Coercivities, Easy axis, Ferromagnetic films, In-plane, Inclination angles, Kinetic equations, Magnetic interactions, Magnetization reversal process, Nanogranulars, Percolation thresholds, Simulation-based, Superparamagnetic grains, Superparamagnetics, Temperature dependence, Temperature range, Thermal activation, Cobalt compounds, Critical currents, Ferromagnetic materials, Ferromagnetism, Integral equations, Magnetic devices, Silicon compounds, Solvents, Superparamagnetism, Magnetization reversal
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-152722DOI: 10.4028/www.scientific.net/SSP.152-153.213ScopusID: 2-s2.0-76149121457ISBN: 390845168XISBN: 978-390845168-6OAI: oai:DiVA.org:kth-152722DiVA: diva2:755057
Forth Moscow International Symposium on Magnetism MISM2008; Moscow; Russian Federation; 20 June 2008 through 25 June 2008
QC 201410132014-10-132014-10-012014-10-13Bibliographically approved