Theoretical and experimental study of FeSi on magnetic and phase properties

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Theoretical and experimental study of FeSi on magnetic and phase properties J. F. Piamba1,2   · C. Ortega3,4 · R. Hernández‑Bravo4 · J. M. González Carmona3,4 · J. A. Tabares1 · G. A. Pérez Alcázar1 · J. M. Alvarado‑Orozco4 Received: 9 April 2020 / Accepted: 29 September 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020

Abstract In the present work, the structural, magnetic, and theoretical analysis of the Fe–Si alloy prepared by melting and heattreated was performed. The ordered FeSi simple cubic (sc) phase was obtained by melting and heat treatment processes as determined by X-ray diffraction. The presence of the superstructure peak in the (312) crystalline direction confirms the high structural order reached. Using Mössbauer spectrometry (MS), a paramagnetic behavior with quadrupole splitting of SQ = 0.53 ± 0.02 mm/s was obtained. Although MS indicates paramagnetic behavior, vibrating sample magnetometry (VSM) showed ferromagnetic behavior with a coercive field of 25 Oe, associated with a small amount of Fe3Si segregations detected by scanning electron microscopy/energy dispersive spectrometry (SEM/EDS). Using density functional theory (DFT), the ­ e3Si, and body-centered cubic (bcc) F ­ e3Si crystalline structures for the simple cubic (sc) F ­ e50Si50, face-centered cubic (fcc) F crystalline structures were simulated. Electron total density values were calculated to perform energetic comparisons with magnetic behavior. The electronic structures and magnetic properties of the Fe–Si alloys in different stoichiometric configurations were calculated by CASTEP, which employed first principles DFT. The density of states (DOS) and band structures were calculated together with magnetic properties. The results showed that the high value of the polarization spin for the fcc and bcc structures is due to the contribution of the high amount of Fe atoms above the Si atoms, which is reflected in an increase in the magnetic moment and that their presence could explain the ferromagnetic behavior observed by VSM. Keywords  Mössbauer spectrometry · X-ray diffraction. · Spin-polarized density functional theory (DFT) calculations · Scanning electron microscopy (SEM)

1 Introduction

* J. F. Piamba [email protected] J. A. Tabares [email protected] 1



Departamento de Física, Universidad del Valle, A.A. 25360, Cali, Colombia

2



Facultad de Ciencias Naturales y Matemáticas, Universidad de Ibagué, Tolima, 730002 Ibagué, Colombia

3

Grupo de Investigación “Recubrimientos Duros y Aplicaciones Industriales RDAI”, Facultad de Ingeniería, Universidad del Valle, A.A. 25360, Cali, Colombia

4

CONACYT-Centro de Ingeniería y Desarrollo Industrial CIDESI, Av. Playa, Av Pie de la Cuesta No. 702, Desarrollo San Pablo, 76125 Santiago de Querétaro, Qro, Mexico





During the last years, the study of the magnetic and electronic transport properties of new materials has been of great interest inside the scientific community, looking for their possible applications. The research on this