Soft Magnetic Properties of High-Entropy Fe-Co-Ni-Cr-Al-Si Thin Films

Pei-Chung Lin,Chun-Yang Cheng,Jien-Wei Yeh,Tsung-Shune Chin

doi:10.3390/e18080308

Pei-Chung Lin, Chun-Yang Cheng + Show 2 more

Open Access

https://doi.org/10.3390/e18080308

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Journal: Entropy	Publication Date: Aug 18, 2016
Citations: 61	License type: CC BY 4.0

Affiliation: National Tsing Hua University, Feng Chia University

Abstract

Soft magnetic properties of Fe-Co-Ni-Al-Cr-Si thin films were studied. As-deposited Fe-Co-Ni-Al-Cr-Si nano-grained thin films showing no magnetic anisotropy were subjected to field-annealing at different temperatures to induce magnetic anisotropy. Optimized magnetic and electrical properties of Fe-Co-Ni-Al-Cr-Si films annealed at 200 °C are saturation magnetization 9.13 × 105 A/m, coercivity 79.6 A/m, out-of-plane uniaxial anisotropy field 1.59 × 103 A/m, and electrical resistivity 3.75 μΩ·m. Based on these excellent properties, we employed such films to fabricate magnetic thin film inductor. The performance of the high entropy alloy thin film inductors is superior to that of air core inductor.

Highlights

Conventional design of a thin film inductor is an air-core spiral
Eddy current loss is inversely proportional to electrical resistivity (ρ) [2]
In order to induce magnetic anisotropy, the as-deposited samples were subjected to field-annealing at temperatures 100 ◦ C, 200 ◦ C, 300 ◦ C, 400 ◦ C, and 500 ◦ C, respectively for one hour under a magnetic field of 7.96 × 104 A/m applied parallel to the film plane

Summary

Introduction

Conventional design of a thin film inductor is an air-core spiral. two disadvantages pronouncedly degrade the performance of air-core spiral in high working frequency. For a magnetic thin film inductor, the higher Ms and Hk , the higher f FMR and the better the performance at high working frequency conditions. HEAs are known with their tendency to have inherently high electrical resistivity and structure stability due to severe lattice distortion and sluggish diffusion [21,22,23]. In consideration of these merits, the present study designed the HEA Fe40 Co35 Ni5 Al5 Cr5 Si10 with high saturation magnetization 9.5 × 105 A/m in Entropy 2016, 18, 308; doi:10.3390/e18080308 www.mdpi.com/journal/entropy.

Experimental Procedures

Microstructure Identification of Fe-Co-Ni-Al-Cr-Si Thin Films

Magnetic

It can be seen seen that hdecreased

Electrical Resistivity of Fe-Co-Ni-Al-Cr-Si Thin Films

Conclusions