Campus Units

Electrical and Computer Engineering, Materials Science and Engineering, Ames Laboratory

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

2-25-2020

Journal or Book Title

Journal of Physics: Condensed Matter

DOI

10.1088/1361-648X/ab79f9

Abstract

A multi-functional Gd5Si1.3Ge2.7 thin film deposited by pulsed laser ablation in the form of an ensemble of nanoparticles was studied for 18 thermal cycles via electron transport measurements together with structural and magnetic characterization. A general negative thermal dependency of the resistivity (ρ) is observed, which contrasts with the metallic-like behavior observed in bulk Gd5SixGe4-x compounds. This general trend is interrupted by a two-step, positive-slope transition in ρ(T) throughout the [150,250]K interval, corresponding to two consecutive magnetic transitions: a fully coupled magnetostructural followed by a purely magnetic order on heating. An avalanche-like behavior is unveiled by the ∂ρ/∂T(T) curves and is explained based on the severe strains induced cyclically by the magnetostructural transition, leading to a cycling evolution of the transition onset temperature (∂T''h/∂n ~ 1.6 K/cycle , n being the number of cycles). Such behavior is equivalent to the action of a pressure of 0.56 kBar being formed and building up at every thermal cycle due to the large volume induced change across the magnetostructural transition. Moreover the thermal hysteresis, detected in both ρ and magnetization versus temperature curves, evolves significantly along the cycles, decreasing as n increases. This picture corroborates the thermal activation energy enhancement - estimated via an exponential fitting of the ∂ρ/∂T(T) in the avalanche regime. This work demonstrates the importance of using a short-range order technique, to probe both pure magnetic and magnetostructural transitions and their evolution with thermal cycles.

Comments

This is a peer-reviewed, un-copyedited version of an article accepted for publication/published in Journal of Physics: Condensed Matter. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at DOI: 10.1088/1361-648X/ab79f9. Posted with permission.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Copyright Owner

IOP Publishing Ltd.

Language

en

File Format

application/pdf

Available for download on Thursday, February 25, 2021

Published Version

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