Morphology and magnetic properties of nanocomposite magnetic multilayers {[(Co$_{40}$Fe$_{40}$B$_{20}$)$_{34}$(SiO$_2$)$_{66}$]/[C]}$_{47}$

TL;DR

This study investigates how the thickness of carbon layers in nanocomposite magnetic multilayers affects their morphology, magnetic, and conductive properties, revealing significant changes in resistance and magnetic behavior despite stable nanoparticle size.

Contribution

It provides new insights into the influence of semiconductor interlayers on the magnetic and conductive properties of nanocomposite multilayers, highlighting the role of interlayer thickness.

Findings

Resistance changes by four orders of magnitude with carbon layer thickness.

Superparamagnetic blocking temperature decreases from 15 K to 7 K.

Nanoparticle size remains largely unchanged despite property variations.

Abstract

We report on the investigation of morphology, magnetic and conductive properties of the mutilayered nanostructures [(Co$_{40}$Fe$_{40}$B$_{20}$)$_{34}$(SiO$_2$)$_{66}$]/[C]$_{47}$ consisting of the contacting magnetic (Co$_{40}$Fe$_{40}$B$_{20}$)$_{34}$(SiO$_2$)$_{66}$ nanocomposite and amorphous semiconductor carbon C layers. It is shown by Grazing-Incidence Small-Angle X-ray Scattering method that the ordering and the size of nanoparticles in the magnetic layers do not change profoundly with increasing of carbon layer thickness. Meanwhile, the electrical conductance and the magnetic properties are significantly varied: resistance of the samples changes by four orders of magnitude and superparamagnetic blocking temperature changes from 15 K to 7 K with the increment of carbon layer thickness $h_c$ from 0.4 nm to 1.8 nm. We assume that the formation of the homogeneous semiconductor interlayer leads to modification of the metal-insulator growth process that drives the changes in the magnetic and conductive properties.