1,721,053 research outputs found
Magnetic information in the light diffratted by Submicron-scale Periodic magnetic arrays
No full textThe experimental and theoretical aspects for obtaining the magnetic information carried by laser beams diffracted from an array of nano-sized magnetic objects is reviewed. Experimentally it will be shown thet the Magneto Optic Kerr Effect (MOKE) hysteresis loops recorded on diffracted beams can be quite different from those recorded in the reflected beam. We will show that the Diffracted-MOKE (D-MOKE) loops are proportional to the magnetic form factor, or equivalently, to the Fourier component of the magnetization corresponding to the reciprocal lattice vector of the diffracted beam. In conjunction with micromagnetic simulations D-MOKE provides powerful and non-destructive technique for investigating the magnetization reversal process in submicron sized magnetic particles
Magnetic information in the light diffracted by submicron-scale periodic magnetic arrays
No full textThe experimental and theoretical aspects for obtaining the magnetic information carried by laser beams diffracted from an array of nano-sized magnetic objects is reviewed. Experimentally it will be shown thet the Magneto Optic Kerr Effect (MOKE) hysteresis loops recorded on diffracted beams can be quite different from those recorded in the reflected beam. We will show that the Diffracted-MOKE (D-MOKE) loops are proportional to the magnetic form factor, or equivalently, to the Fourier component of the magnetization corresponding to the reciprocal lattice vector of the diffracted beam. In conjunction with micromagnetic simulations D-MOKE provides powerful and non-destructive technique for investigating the magnetization reversal process in submicron sized magnetic particles
Biquadratic exchange coupling in an unequal Fe/Cr/Fe (100) trilayer
No full textWe have investigated the magnetic properties of a (1 0 0)-oriented unequal trilayer, Fe(45 angstroms)/Cr(30 angstroms)/Fe(15 angstroms), by means of Brillouin light scattering and magnetization measurements. The experimental results show that this sample highlights the effect of biquadratic coupling which aligns the magnetization of the Fe layers at 90 °C to each other. We extracted the bilinear and biquadratic coupling strengths by fitting the experimental results with a theory that treats the static and dynamic responses on an equal footing. Our results confirm that the model describes both the static and dynamic properties even when the magnetization of the layers is aligned at 90°. The coupling strengths, and their temperature dependence, are discussed and compared with other results reported in the literature
Magnetic field effects on the NiO magnon spectra
Full text linkThe effect of an external magnetic field on the eight antiferromagnetic resonance AFMR modes of NiO hasbeen studied experimentally using Brillouin light scattering. The results are reproduced by a model thatincludes the effects of exchange, dipolar coupling, a small cubic anisotropy, and Zeeman terms. Magnetic fieldsup to 7 T were applied along several NiO crystalline directions. The agreement between theory and experimentprovides additional proof that the model, recently introduced to explain the existence of the AFMR multiplet,is indeed valid. Deviations between simulations and experiments, together with a review of previously publishedresults, indicate that large magnetostrictive effects are present in NiO.Fil: Milano, Julian. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Grimsditch, M.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentin
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Dynamic origin of stripe domains
No full textWe investigate stripe domain formation in nanometer sized Co bars. The magnetic equilibrium states and the magnetic spin wave frequencies are obtained from micromagnetic-like simulations. We find that the lowest frequency standing-wave mode has the same spatial structure as the stripe domains at remanence and it goes soft at the field where the stripe domains emerge. We show, therefore, that the final domain structure at remanence, which is not the configuration with lowest energy, is predicted from a high-field analysis of the frequencies of the standing spin waves
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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