Magnetic hysteresis control in thin film Fe/Si multilayers by incorporation of B4C

TL;DR

This study investigates how B4C incorporation in Fe/Si multilayers affects magnetic properties, revealing tunability of coercivity and magnetization through controlled amorphization, with implications for data storage and spintronics.

Contribution

It demonstrates that B4C addition induces amorphization in Fe/Si multilayers, enabling precise control of magnetic properties for advanced device applications.

Findings

Adding B4C lowers coercivity and saturation magnetization.

10-15% B4C induces antiferromagnetic coupling.

B atoms occupy interstitial sites, causing amorphization.

Abstract

Magnetic hysteresis properties in Fe/Si multilayers have been studied as a function of the B4C content to control magnetization amplitude, coercivity, and hysteresis tilt, properties that are beneficial to tune for advancing applications in e.g. data storage, spintronics, and sensors. With an ion-assisted magnetron sputtering technique, 35 distinct thin film multilayer samples were prepared and their magnetic and structural properties were characterized by vibrating sample magnetometry, X-ray photoelectron spectroscopy, near edge X-ray absorption fine structure spectroscopy, and X-ray and neutron scattering methods. Key findings indicate that adding B4C lowers the coercivity and can decrease the saturation magnetization, demonstrating the tunability of magnetic responses based on composition. For samples with =30{\AA} periodicity, 10-15% of B4C addition produces antiferromagnetically (AF) coupled multilayers, and such AF coupling strength increases with the B4C content. Our findings reveal that B atoms do not chemically bind within the Fe atoms but instead occupy interstitial positions, disrupting medium- to long-range crystallinity thereby inducing the amorphization. Thereon, the observed effects on magnetic properties are directly attributed to this amorphization process caused by the presence of B4C. The demonstrated ability to finely adjust magnetic properties by varying the B4C content offers a promising approach to overcome challenges in magnetic device performance and efficiency.