Edson Massayuki Kakuno

Structure, Composition, and Morphology of Electrodeposited Co x Fe1 − x Alloys

We have investigated the structure, composition, and morphology of Co x Fe 1-x alloys prepared on copper substrates under potentiostatic electrodeposition conditions currently used to produce composition modulated alloys. Co x Fe 1-x alloys with x = 1 to 0 have been obtained by simple control of the Co 2+ : Fe 2+ ratio in the bath solutions using the characteristic behavior of the codeposition of the metals. The alloy composition was determined by energy dispersive spectroscopy. X-ray analysis of the structure of deposits indicates texture with coexistence of phases. For higher iron concentrations the alloys are mostly body-centered-cubic with (110) preferred orientation. For higher cobalt concentrations the alloys become mostly hexagonal with (0001) preferred orientation. Scanning electron microscopy was used to analyze the deposit morphology. Except for alloy concentrations of about x = 0.7, where a nonuniform character of deposits with partial cobalt segregation has been observed, the Co-Fe alloys have a rather uniform composition and morphology in the cathodic potentials used for electrodeposition

Structure, Composition, and Morphology of Electrodeposited Co0.9Fe0.1 ( Cu ) Alloys

The successful use of the electrochemical process to produce compositional heterogeneous Co{sub 0.9}Fe{sub 0.1}(Cu) alloys is shown. Structure, composition, and morphology of the heterogeneous alloyed films, produced by the potentiostatic method, has been investigated by means of different techniques. Energy dispersive spectroscopy analyses reveal that the total amount of Co and Fe in the electrodeposits is strongly dependent on the Cu concentration in the plating solution at the potentiodynamic range investigated. The Co:Fe ratio does not change drastically due to Cu incorporation in the electrodeposits. It was also observed that by increasing the Cu content in the electrodeposits a granular morphology is obtained. Transmission electron microscopy was used to characterize the micromorphology and the heterogeneous composition of the alloys. The polycrystalline character of electrodeposits with a predominant face-centered cubic structure was characterized by using selected area electron diffraction and x-ray diffraction measurements.

Long and compact x-ray pathway for experiments requiring high coherent x-ray beams.

A long x-ray pathway based on an x-ray back-diffraction cavity for coherent x-ray beam experiments is presented. In the present work, such a setup was tested and used for propagation-based x-ray phase contrast imaging (PBI). This setup showed to be useful for PBI purposes, with the advantage of being compact (3 m long) when compared with long x-ray synchrotron beamlines with dimensions from tens to hundreds of meters.

Uso da plataforma Arduino e do software PLX-DAQ para construção de gráficos de movimento em tempo real

This paper presents an educational tool developed using the Arduino platform with a position sensor and the PLX-DAQ software, which was used in developing a learning experiment suitable for teaching graphics kinematics that was applied to the masters work. The aim was to overcome learning difficulties faced by students of basic education in the construction and interpretation of graphs, like position versus time in the Cartesian coordinate system. We present a detailed description of instrumentation and some results of an implementation carried out with two groups of 1st year of high school, a State school in the city of Candiota / RS. In the implementation, we identified an increase in student performance, which demonstrated certain difficulties in the analysis and interpretation of motion graphics at the beginning of the activity; however, they developed skills in the course of tasks, achieving both qualitative and quantitative results (statistically significant). The students were able to interpret and reproduce motion graphics in real time from the instrumentation proposed in this work.

Montagem e teste de detector Geiger Muller usando tubo SBM19

Este trabalho descreve a montagem de um detector Geiger Muller (GM) a partir de um tubo comercial, SBM19, e com flexibilidade nos componentes eletronicos agregados. Muitas referencias citadas sao de dominio publico e disponiveis na internet, permitido ao leitor uma maior facilidade ao acesso as informacoes e a outras possibilidades de montagem de um detector GM. O detector proposto e uma ferramenta em potencial para o ensino de fisica moderna no Ensino Medio e uma proposta de demonstracao em feiras de ciencias. Sao apresentados resultados de medidas em camisas de lampiao, Am de um detector de fumaca e de um cinzeiro enriquecido com urânio.

Exotic X-ray back-diffraction: a path toward a soft inelastic X-ray scattering spectrometer

In this work, soft X-ray back-diffraction (XBD; X-ray diffraction at angles near and exactly equal to 90°) is explored. The experiment was conducted at the SXS beamline at Laboratorio Nacional de Luz Sincrotron, Brazil, at ∼3.2 keV. A high-resolution Si(220) multi-bounce back-diffraction monochromator was designed and constructed for this experiment. An ultra-thin Si(220) crystal (5 µm thick) was used as the sample. This ultra-thin crystal was characterized by profilometry, rocking-curve measurements and X-ray topography prior to the XBD measurements. It is shown that the measured forward-diffracted beam (o-beam) profiles, taken at different temperatures, are in close agreement with profiles predicted by the extended dynamical theory of X-ray diffraction, with the absence of multiple-beam diffraction (MBD). This is an important result for future studies on the basic properties of back-diffracted X-ray beams at energies slightly above the exact XBD condition (extreme condition where XBD is almost extinguished). Also, the results presented here indicate that stressed crystals behave like ideal strain-free crystals when used for low-energy XBD. This is mainly due to the large widths of XBD profiles, which lead to a low strain sensitivity in the detection of defects. This result opens up new possibilities for mounting spherical analyzers without degrading the energy resolution, at least for low energies. This is a path that may be used to construct a soft inelastic X-ray scattering spectrometer where different applications such as element-specific magnetic imaging tools could be explored.