Interfacial tuning of perpendicular magnetic anisotropy and spin magnetic moment in CoFe/Pd multilayers

TL;DR

This study demonstrates how interfacial engineering in CoFe/Pd multilayers influences perpendicular magnetic anisotropy and magnetic moments, revealing the dominant role of surface and interface effects on magnetic properties.

Contribution

It provides new insights into tuning magnetic anisotropy and moments through interfacial control in CoFe/Pd multilayers using advanced spectroscopic techniques.

Findings

Perpendicular magnetic anisotropy is strong in CoFe/Pd multilayers.

Magnetic moments decrease with increasing Pd spacer thickness.

Surface and interface effects significantly impact magnetic properties.

Abstract

We report on a strong perpendicular magnetic anisotropy in [CoFe 0.4nm/Pd t]6 (t = 1.0-2.0 nm) multilayers fabricated by DC sputtering in a ultrahigh vacuum chamber. Saturation magnetization, $M_s$, and uniaxial anisotropy, $K_u$, of the multilayers decrease with increasing the spacing thickness, with a $M_s$ of 155 emu/cc and a $K_u$ of 1.14$\times 10^5$ J/m$^3$ at a spacing thickness of t = 2 nm. X-ray absorption spectroscopy and X-ray magnetic circular dichroism measurements reveal that spin and orbital magnetic moments of Co and Fe in CoFe film decrease as function of Pd thickness, indicating the major contribution of surface/interfacial magnetism to the magnetic properties of the film.