An advancement in the synthesis of unique soft magnetic CoCuFeNiZn high entropy alloy thin films

Chokkakula L P Pavithra,Yixuan Hu,Joydip Joardar,Reddy Kunda Siri Kiran Janardhana,Kolan Madhav Reddy,Rameez R Tamboli,Xiaodong Wang,Yumeng Zhang,Chandrasekhar Murapaka,Suhash Ranjan Dey,Bulusu V Sarada

doi:10.1038/s41598-021-87786-8

Abstract

Discovery of advanced soft-magnetic high entropy alloy (HEA) thin films are highly pursued to obtain unidentified functional materials. The figure of merit in current nanocrystalline HEA thin films relies in integration of a simple single-step electrochemical approach with a complex HEA system containing multiple elements with dissimilar crystal structures and large variation of melting points. A new family of Cobalt–Copper–Iron–Nickel–Zinc (Co–Cu–Fe–Ni–Zn) HEA thin films are prepared through pulse electrodeposition in aqueous medium, hosts nanocrystalline features in the range of ~ 5–20 nm having FCC and BCC dual phases. The fabricated Co–Cu–Fe–Ni–Zn HEA thin films exhibited high saturation magnetization value of ~ 82 emu/g, relatively low coercivity value of 19.5 Oe and remanent magnetization of 1.17%. Irrespective of the alloying of diamagnetic Zn and Cu with ferromagnetic Fe, Co, Ni elements, the HEA thin film has resulted in relatively high saturation magnetization which can provide useful insights for its potential unexplored applications.

Highlights

Discovery of advanced soft-magnetic high entropy alloy (HEA) thin films are highly pursued to obtain unidentified functional materials
The development of HEAs with a new set of elements having three distinct crystal structures and large variation in their melting points, in the form of bulk or thin films have not been explored except ball milling due to the difficulty faced during conventional high temperature alloy making methods
The present study demonstrates new aqueous medium-assisted nanocrystalline dual phase HEA thin films containing unique combination of five elements (Co–Cu–Fe–Ni–Zn) by a cost effective, single step electrochemical deposition which has not been attempted till

Summary

Introduction

Discovery of advanced soft-magnetic high entropy alloy (HEA) thin films are highly pursued to obtain unidentified functional materials. The development of HEAs with a new set of elements having three distinct crystal structures and large variation in their melting points (low melting point element such as Zn), in the form of bulk or thin films have not been explored except ball milling due to the difficulty faced during conventional high temperature alloy making methods. Fabricating this alloy system in a single step at lower temperatures (close to room temperature) in the form of films or coatings is only possible by electrodeposition in aqueous electrolyte based on their ability to reduce electrochemically which does not involve. Application of pulse allows control over composition and microstructure that in turn can tune the properties thereby facilitating large scale production simultaneously

Methods

Results

Conclusion