A new magnetostrictive material

A new arsenide with two magnetic species displays unconventional thermoelastic response as a result of crystal structure flexibility.

To the point:

• A new quantum material: A large negative thermal expansion is observed.
• Special crystal architecture: Diverse thermoelastic response exists within the same lattice.
• Potential application potential: The study identifies this and related systems as a route towards materials with tunable thermoelastic properties.

An international research team has identified a new material with unconventional thermoelastic response. The strong coupling between crystal structure and magnetism in SmFe₅As₃ leads to unusual volumetric behavior driven by changes in temperature or magnetic field. Its magnetic behavior is governed by two distinct magnetic sublattices (Sm and Fe), giving rise to positive, negative, and even nearly zero thermal expansion along the [010] direction of the needle-shaped crystal. The most remarkable effect is a regime of giant thermal expansion observed between 42 and 100 K, where the expansion reaches values as high as 2500 × 10^-6 - a value comparable to materials that are currently used in applications.

This work establishes SmFe₅As₃ as a new platform for tunable thermal expansion. Discovery of this peculiar material not only deepens our understanding of magnetism, but also offers a potential avenue towards applications.

This work was published in Angewandte Chemie International Edition as a cover

and highlighted in Hot Topic: Magnetic Materials.

 

MPI CPfS, ES