Lattice Dynamics of Martensitic Transformations Examined by Atomistic Simulations

We have performaed molecular dynamics simulations of Fe(80)Ni(20) alloys using an inter-atomic potential of the EAM-type which allows the simulation of the martensite-austenite transition. We present results, showing the development of an inhomogeneous shear system on a nanoscale during the thermally induced austenitic transition. In addition to this we obtained the phonon dispersion relations of the martensite phase by calculating the dynamical structure factor from our simulation results. On approaching the transition temperature the phonon dispersion shows anomalies which might be connected with the formation of the microstructure during the austenitic transition.Comment: 7 pages, 4 figures, Contribution submitted to the "IV European Symposium on Martensitic Transformations" (ESOMAT 97), July 1-5, 1997, Enschede (The Netherlands

Ab initio study of the interface properties of Fe/GaAs(110)

We have investigated the initial growth of Fe on GaAs(110) by means of density functional theory. In contrast to the conventionally used (001)-surface the (110)-surface does not reconstruct. Therefore, a flat interface and small diffusion can be expected, which makes Fe/GaAs(110) a possible candidate for spintronic applications. Since experimentally, the actual quality of the interface seems to depend on the growth conditions, e.g., on the flux rate, we simulate the effect of different flux rates by different Fe coverages of the semiconductor surface. Systems with low coverages are highly diffusive. With increasing amount of Fe, i.e., higher flux rates, a flat interface becomes more stable. The magnetic structure strongly depends on the Fe coverage but no quenching of the magnetic moments is observed in our calculations.Comment: 9 pages, 8 figure

As telenovelas como geradoras de estereótipos de gênero: o caso do México

Las telenovelas han contribuido a la reproducción de los estereotipos de género que se introducen en el imaginario colectivo como una normalidad. Sus historias representan mujeres con roles pasivos, víctimas de discriminación, violencia, sexualidad y cosificación. El objetivo de este artículo es analizar cómo los estereotipos contribuyen al mantenimiento del sistema sexo-género como un constructo cultural inequitativo. El método utilizado para su elaboración fue una investigación documental con datos y testimonios sobre los papeles que juegan los sujetos femeninos en las telenovelas. Uno de los hallazgos a destacar es la persistencia de interpretaciones poco apegadas  la realidad, que no dan cuenta de la transformación de los roles de la vida moderna. ntre las conclusiones más significativas de este artículo hay que señalar el escaso compromiso de las televisoras para contribuir al cambio cultural presentando a mujeres reales como protagonistas de sus historias.Soap Operas have contributed to the reproduction of gender stereotypes that are introduced in the collective imagination as a normality. Their stories represent women with passive roles, victims of discrimination, violence, sexuality, and reification. The objective of this article is to analyze how stereotypes contribute to the maintenance of the sex-gender system as an inequitable cultural construct. The method used for its elaboration was a documentary investigation with data and testimonies about the roles played by female subjects in soap operas. One of the findings to be highlighted is the persistence of interpretations little attached to reality, which do not account for the transformation of the roles of modern life. Among the most significant conclusions of this article is the lack of commitment of television stations to contribute to cultural change by presenting real women as protagonists of their stories.As telenovelas contribuem para a reprodução dos estereótipos de gênero que são introduzidos no imaginário coletivo como uma normalidade. Suas histórias representam mulheres com papéis passivos, vítimas de preconceito, violência, sexualidade e coisificação. O objetivo deste artigo é analisar como os estereótipos promovem a manutenção do sistema sexogênero como um construto cultural desigual. O método utilizado para sua elaboração foi uma pesquisa documental com dados e depoimentos sobre os papéis que os sujeitos femininos desempenham nas telenovelas. Um dos achados que se destaca é a persistência de interpretações pouco atreladas à realidade, que não dão conta da transformação dos papéis na vida moderna. Entre as conclusões mais significativas deste artigo, há o escasso compromisso dos canais de televisão para contribuir para a mudança cultural apresentando mulheres reais como protagonistas de suas histórias.https://revistas.udem.edu.co/index.php/anagramas/article/view/194

Density functional simulation of small Fe nanoparticles

We calculate from first principles the electronic structure, relaxation and magnetic moments in small Fe particles, applying the numerical local orbitals method in combination with norm-conserving pseudopotentials. The accuracy of the method in describing elastic properties and magnetic phase diagrams is tested by comparing benchmark results for different phases of crystalline iron to those obtained by an all-electron method. Our calculations for the bipyramidal Fe_5 cluster qualitatively and quantitatively confirm previous plane-wave results that predicted a non-collinear magnetic structure. For larger bcc-related (Fe_35) and fcc-related (Fe_38, Fe_43, Fe_62) particles, a larger inward relaxation of outer shells has been found in all cases, accompanied by an increase of local magnetic moments on the surface to beyond 3 mu_B.Comment: 15 pages with 6 embedded postscript figures, updated version, submitted to Eur.Phys.J.