Phonon anomaly and local distortion in iron-manganese-based Elinvar alloys

This paper examines the phonon dispersion and static local atomic distortion of iron-manganese-based Elinvar alloys using high-resolution inelastic X-ray scattering, magnetization, neutron diffraction, and neutron total scattering. In this study, nonlinear phonon dispersion was observed for a transv...

Full description

Saved in:
Bibliographic Details
Main Authors: Yoshihiko Umemoto, Yoichi Ikeda, Takashi Honda, Daisuke Ishikawa, John A. Schneeloch, Jörg C. Neuefeind, Shinichiro Tozawa, Rie Umetsu, Despina Louca, Alfred Q.R. Baron, Masaki Fujita
Format: Article
Language:English
Published: Taylor & Francis Group 2025-07-01
Series:Science and Technology of Advanced Materials
Subjects:
Online Access:https://www.tandfonline.com/doi/10.1080/14686996.2025.2540278
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper examines the phonon dispersion and static local atomic distortion of iron-manganese-based Elinvar alloys using high-resolution inelastic X-ray scattering, magnetization, neutron diffraction, and neutron total scattering. In this study, nonlinear phonon dispersion was observed for a transverse acoustic mode near zone center, associated with [Formula: see text] elastic constants, over a wide temperature range along the [Formula: see text] to X (310) points of the face-centered cubic system, indicating lattice instability coupled with tetragonal distortions in the long-wavelength limit. Bulk magnetization and neutron diffraction measurements suggest that the conventional ferromagnetic magnetostriction scenario is not the origin of Elinvar characteristics. Instead, the martensitic transformation and lattice instabilities underlie these phenomena. The reduced pair distribution function reveals a significant discrepancy between local and global (averaged) structures suggesting the influence of atomic-scale lattice disorder and instability in FeMn-based Elinvar alloys.
ISSN:1468-6996
1878-5514