1,721,038 research outputs found
Magnetization steps in nanomagnets induced by a time-dependent magnetic field: Application to Fe4
No full textRelaxation time of the nanomagnet Fe4
No full textThe magnetic behaviour of the molecular nanomagnet Fe4 is very well simulated by a single spin model Hamiltonian in a crystal field with S=5. The crystal field parameters were determined from the inelastic neutron scattering (INS) spectra. Here we show that the quantum effects are crucial to understand the saturation of the relaxation time observed at very low temperature at variance with the standard master equation result that leads to an Arrhenius law at any temperature. Very deep downward spikes in correspondence of the anticrossing fields are found in the relaxation time versus field at low temperature. We compare our results with those obtained by previous approaches worked out to fit experimental data on Mn12
Phase diagram of a square Ising model with exchange and dipole interactions: Monte Carlo simulations.
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Order-disorder phase transition in two-dimensional Ising Model with exchange and dipole interactions
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dilatometric study of shrinkage during sintering process for porcelain stoneware body in presence of nepheline syenite
No full textThe shrinkage of porcelain stoneware body containing different values of nepheline syenite was investigated. Dilatomeric tests were carried out on suitable specimens to obtain the expansion-shrinkage behavior of ceramic bodies. The differences found in shrinkage data were evaluated by kinetic model and determination of activation energy. The results showed that the activation energy increases with Na2O+K2O/quartz ratio and reaches to constant
value when 10.0 wt.% nepheline syenite is added to starting composition. The maximum value of shrinkage also approximately remains constant with increasing fluxing agent. It was found that the fluxing effect of nepheline syenite was quite evident with the observed enhanced rate of densification accompanied by the typical compensation effect
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