Spatially confined magnetic shape-memory Heuslers: Implications for nanoscale devices

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F26%3A0197793" target="_blank" >RIV/00216305:26620/26:0197793 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S1359645424009273" target="_blank" >https://www.sciencedirect.com/science/article/pii/S1359645424009273</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.actamat.2024.120579" target="_blank" >10.1016/j.actamat.2024.120579</a>

Result language

angličtina

Original language name

Spatially confined magnetic shape-memory Heuslers: Implications for nanoscale devices

Original language description

Magnetic shape-memory (MSM) Heuslers are among the most promising materials for thermo-magneto-mechanical applications. However, the knowledge about the martensitic transformation (which is the basis of the multifunctionality in these materials) as a function of size reduction in the submicron scale is still very limited. Here, we aim to bridge this knowledge gap by investigating the behavior of these materials upon nanoscale confinement. We customize a top-down approach by patterning arrays of submicron epitaxial Ni-Mn-Ga structures with lateral sizes down to similar to 70 nm, using a Cr hard mask on MgO(001) substrate. The structures include straight stripes, radial stripes, squares and triangles. The martensitic transformation temperature, sharpness, thermal hysteresis and magnetic characteristics of the material are investigated upon spatial confinement. Transmission electron microscopy techniques including Geometric Phase Analysis (GPA) algorithm, and quantitative theoretical analysis of stress help us to evaluate the martensitic transformation of Ni-Mn-Ga starting from continuous films and down to sub-micron patterns. We show that the size-dependent internal stress relaxation plays a primary role in broadening the martensitic transformation of the material, reducing thermal hysteresis, and pushing the transformation toward higher temperatures in the sub-micron structures. These findings highlight the importance of stress considerations upon incorporation of MSM Heusler materials into nanoscale functional devices.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

20500 - Materials engineering

Project

—

Continuities

—

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Acta materialia

ISSN

1359-6454

e-ISSN

1873-2453

Volume of the periodical

284

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

11

Pages from-to

1-11

UT code for WoS article

001371317900001

EID of the result in the Scopus database

2-s2.0-85210066092