By a News Reporter-Staff News Editor at Energy Weekly News -- Current study results on General Chemical Research have been published. According to news reporting from Espoo, Finland, by VerticalNews journalists, research stated, "The stability of magnetic states and the mechanism for magnetic transitions can be analyzed in terms of the shape of the energy surface, which gives the energy as a function of the angles determining the orientation of the magnetic moments. Minima on the energy surface correspond to stable or metastable magnetic states and can represent parallel, antiparallel or, more generally, non-collinear arrangements."
The news correspondents obtained a quote from the research from Aalto University, "A rate theory has been developed for systems with arbitrary number, N, of magnetic moments, to estimate the thermal stability of magnetic states and the mechanism for magnetic transitions based on a transition state theory approach. The minimum energy path on the 2N-dimensional energy surface is determined to identify the transition mechanism and estimate the activation energy barrier. A pre-exponential factor in the rate expression is obtained from the Landau-Lifshitz-Gilbert equation for spin dynamics. The velocity is zero at saddle points so it is particularly important in this context to realize that the transition state is a dividing surface with 2N - 1 degrees of freedom, not just a saddle point. An application of this rate theory to nanoscale Fe islands on W(110) has revealed how the transition mechanism and rate depend on island shape and size. Qualitative agreement is obtained with experimental measurements both for the activation energy and the pre-exponential factor. In particular, a distinct maximum is observed in the pre-exponential factor for islands where two possible transition mechanisms are competing: Uniform rotation and the formation of a temporary domain wall."
According to the news reporters, the research concluded: "The entropy of the transition state is enhanced for those islands making the pre-exponential factor more than an order of magnitude larger than for islands were only the uniform rotation is viable."
For more information on this research see: Potential Energy Surfaces and Rates of Spin Transitions. Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics, 2013;227(9-11):1543-1557. Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics can be contacted at: Walter De Gruyter Gmbh, Genthiner Strasse 13, D-10785 Berlin, Germany.
Our news journalists report that additional information may be obtained by contacting P.F. Bessarab, Aalto Univ, Dept. of Appl Phys, FI-00076 Espoo, Finland. Additional authors for this research include V.M. Uzdin and H. Jonsson.
Keywords for this news article include: Espoo, Europe, Finland, Energy Companies, General Chemical Research
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