Issue 24, 2019

Cation diffusion patterns across the magneto-structural transition in Fe7S8

Abstract

Migration of atoms in solids during diffusion-dependent reactions is relatively fast and generally not directly recordable in experiments. Here we present an experimental framework that includes fast differential scanning calorimetry to resolve cation-migration paths in crystalline solids using the reversible magneto-structural transition of 4C to 1C pyrrhotite as a testbed. The transition between these two polymorphic Fe7S8 phases at about 600 K is a diffusive process of vacancies, respectively of Fe in octahedral interstitial sites within a hexagonal close-packed lattice of sulfur, and it coincides with the Curie temperature of 4C pyrrhotite. The Fe cations migrate along three kinds of diffusion paths, and their enthalpy contributions to the total reaction enthalpy are taken to define the diffusion patterns in the endothermic reaction and the exothermic back-reaction, respectively. Our experimental findings provide insight into the potential of diffusion patterns to disentangle ordering mechanisms in solids.

Graphical abstract: Cation diffusion patterns across the magneto-structural transition in Fe7S8

Article information

Article type
Paper
Submitted
11 Mar 2019
Accepted
30 May 2019
First published
30 May 2019
This article is Open Access
Creative Commons BY-NC license

Phys. Chem. Chem. Phys., 2019,21, 13040-13046

Cation diffusion patterns across the magneto-structural transition in Fe7S8

D. Koulialias, P. G. Weidler, M. Charilaou, J. F. Löffler and A. U. Gehring, Phys. Chem. Chem. Phys., 2019, 21, 13040 DOI: 10.1039/C9CP01387C

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements