Jump to main content
Jump to site search


Negative thermal expansion in (Sc,Ti)Fe2 induced by an unconventional magnetovolume effect

Author affiliations

Abstract

Negative thermal expansion (NTE) has been found in some magnetic functional materials due to the magnetovolume effect (MVE), in which an order-to-disorder magnetic transition occurs. Here, we report an unconventional MVE which can induce the crossover from the common positive thermal expansion of the end members of ScFe2 and TiFe2 to the NTE in the solid solution of (Sc1−xTix)Fe2 (x = 0.6, αV = −28.36 × 10−6 K−1, 125–205 K). The direct evidence of neutron powder diffraction and first-principles calculations discloses that the decrease of intrinsic magnetic moments at the Fe(2a) site results in the ferromagnetic transition from one to another, which causes a stronger negative contribution to thermal expansion than the conventional MVE. The pair distribution function analysis verifies that the decrease in the nearest distance of Fe(6h)–Fe(6h) lying in the ab plane results in the shrinkage of the a(b) axis. The analysis of anisotropic atomic displacement parameters excludes the phonon induced NTE mechanism. Furthermore, an intriguing zero thermal expansion has been found in Sc0.55Ti0.45Fe2 (10–250 K). The present study provides an approach to achieve NTE or controllable thermal expansion, which may be used to enhance other magnetic-related effects, such as the magnetocaloric and barocaloric effect.

Graphical abstract: Negative thermal expansion in (Sc,Ti)Fe2 induced by an unconventional magnetovolume effect

Back to tab navigation

Supplementary files

Publication details

The article was received on 03 Jul 2019, accepted on 16 Sep 2019 and first published on 17 Sep 2019


Article type: Communication
DOI: 10.1039/C9MH01025D
Mater. Horiz., 2019, Advance Article

  •   Request permissions

    Negative thermal expansion in (Sc,Ti)Fe2 induced by an unconventional magnetovolume effect

    Y. Song, Q. Sun, M. Xu, J. Zhang, Y. Hao, Y. Qiao, S. Zhang, Q. Huang, X. Xing and J. Chen, Mater. Horiz., 2019, Advance Article , DOI: 10.1039/C9MH01025D

Search articles by author

Spotlight

Advertisements