Publication detail

Spin stress contribution to the lattice dynamics of FePt

VON REPPERT, A. WILLIG, L. PUDELL, J. ZEUSCHNER, S. SELLGE, G. GANSS, F. HELLWIG, O. ARREGI URIBEETXEBARRIA, J. UHLÍŘ, V. CRUT, A. BARGHEER, M.

Original Title

Spin stress contribution to the lattice dynamics of FePt

Type

journal article in Web of Science

Language

English

Original Abstract

Invar-behavior occurring in many magnetic materials has long been of interest to materials science. Here, we show not only invar behavior of a continuous film of FePt but also even negative thermal expansion of FePt nanograins upon equilibrium heating. Yet, both samples exhibit pronounced transient expansion upon laser heating in femtosecond x-ray diffraction experiments. We show that the granular microstructure is essential to support the contractive out-of-plane stresses originating from in-plane expansion via the Poisson effect that add to the uniaxial contractive stress driven by spin disorder. We prove the spin contribution by saturating the magnetic excitations with a first laser pulse and then detecting the purely expansive response to a second pulse. The contractive spin stress is reestablished on the same 100-ps time scale that we observe for the recovery of the ferromagnetic order. Finite-element modeling of the mechanical response of FePt nanosystems confirms the morphology dependence of the dynamics.

Keywords

THERMAL-EXPANSION; ORIGIN

Authors

VON REPPERT, A.; WILLIG, L.; PUDELL, J.; ZEUSCHNER, S.; SELLGE, G.; GANSS, F.; HELLWIG, O.; ARREGI URIBEETXEBARRIA, J.; UHLÍŘ, V.; CRUT, A.; BARGHEER, M.

Released

1. 6. 2020

Publisher

AAAS

Location

WASHINGTON

ISBN

2375-2548

Periodical

Science Advances

Year of study

6

Number

28

State

United States of America

Pages from

1

Pages to

7

Pages count

7

URL

https://advances.sciencemag.org/content/6/28/eaba1142

Full text in the Digital Library

http://hdl.handle.net/11012/196729

BibTex

@article{BUT165274,
  author="Alexander {von Reppert} and Lisa {Willig} and Jan Etienne {Pudell} and Steffen Peer {Zeuschner} and Gabriel {Sellge} and Fabian {Ganss} and Olaf {Hellwig} and Jon Ander {Arregi Uribeetxebarria} and Vojtěch {Uhlíř} and Aurelien {Crut} and Matias {Bargheer}",
  title="Spin stress contribution to the lattice dynamics of FePt",
  journal="Science Advances",
  year="2020",
  volume="6",
  number="28",
  pages="1--7",
  doi="10.1126/sciadv.aba1142",
  issn="2375-2548",
  url="https://advances.sciencemag.org/content/6/28/eaba1142"
}