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Your search keyword '"Nóbrega, E.P."' showing total 37 results
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37 results on '"Nóbrega, E.P."'

28. Magnetic and magnetocaloric properties in Gd1−yPryNi2 compounds

Author

Alho, B.P., primary, Lopes, P.H.O., additional, Ribeiro, P.O., additional, Alvarenga, T.S.T., additional, Nóbrega, E.P., additional, de Sousa, V.S.R., additional, Carvalho, A.M.G., additional, Caldas, A., additional, Tedesco, J.C.G., additional, Coelho, A.A., additional, de Oliveira, N.A., additional, and von Ranke, P.J., additional

Published
2018
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36. Theoretical investigation on the magnetocaloric effect in amorphous [formula omitted] system.

Author

Costa, S.S., Roriz, O.A.V., Silvano, N. de O., von Ranke, P.J., and Nóbrega, E.P.

Subjects
*MAGNETOCALORIC effects, *AMORPHOUS substances, *MAGNETIC properties of metals, *AMORPHIZATION, *MOLECULAR structure
Abstract

In this work, we investigated the magnetic and magnetocaloric properties of the amorphous system Eu 80 Au 20 . The magnetic state equation and entropy were considered in the framework of Handrich–Kaneyoshi model, which takes into account the amorphization through the symmetric exchange fluctuation in the mean field approximation. The exchange and structural fluctuations parameters were chosen based on the experimental data of Eu 80 Au 20 . The isothermal entropy change was calculated for several variations of external magnetic field. Furthermore, the adiabatic temperature change and the refrigerant capacity were calculated for a magnetic field change from 0 to 5 T. [ABSTRACT FROM AUTHOR]

Published
2016
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37. Theoretical investigations on the magnetocaloric and barocaloric effects in Tb y Gd(1− y )Al2 series

Author

Ribeiro, P.O., Alho, B.P., Alvarenga, T.S.T., Nóbrega, E.P., Carvalho, A.Magnus G., de Sousa, V.S.R., Caldas, A., de Oliveira, N.A., and von Ranke, P.J.

Subjects
*PHYSICAL & theoretical chemistry, *MAGNETOCALORIC effects, *TERBIUM, *FERROMAGNETISM, *NUMERICAL calculations, *MAGNETIC ions, *ELECTRIC fields, *ZEEMAN effect
Abstract

Abstract: We report the calculations on the magnetocaloric and barocaloric effects in ferromagnetic series Tb y Gd(1− y )Al2. Our model includes the crystalline electrical field interaction, exchange interactions among Tb–Tb, Gd–Gd and Tb–Gd magnetic ions and the Zeeman effect for an anisotropic system. The lattice and electronic entropies were included in adiabatic processes. The magnetocaloric effect calculated for magnetic field changes along the easy magnetic direction 〈111〉 is in good agreement with the experimental data. Calculation along the hard magnetization direction 〈001〉 predicts anomalous magnetocaloric effect, which was ascribed to the spin reorientation processes. From the available experimental data of Curie temperature dependence on pressure, the exchange model parameters were scaled and the barocaloric effect was calculated. [Copyright &y& Elsevier]

Published
2013
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