Influence of buffer/protective layers on the structural and magnetic properties of SmCo films on Silicon

TL;DR

This study investigates how different buffer/protective layers and annealing temperatures affect the structural and magnetic properties of SmCo films on silicon, achieving some of the highest coercivity values reported.

Contribution

It provides a comparative analysis of five buffer layers and two annealing temperatures, optimizing process parameters for enhanced magnetic properties of SmCo films.

Findings

Coercivity up to 3.65 T achieved with proper buffer layer and annealing.

Saturation magnetization up to 0.95 T obtained.

High coercivity values among the best in literature for SmCo thin films.

Abstract

Integration of Samarium Cobalt hard magnets on silicon requires buffer/protective layers that can enhance the magnetic properties of the magnet while preserving its structure and chemical composition after post-annealing treatments needed for the formation of the magnetically hard phase. In this work, a comparison of Samarium-Cobalt films for five different buffer/protective layers, namely Ti, W, TiW, Ta, Cr and two different annealing temperatures, 650{\deg}C and 750{\deg}C, is presented. Depending on materials and annealing temperatures, magnetic properties such as saturation and coercivity of the SmCo film can be finely tuned. We show that coercivity up to 3.65 T or saturation magnetization up to 0.95 T can be reached by proper choice of the relevant process parameters: deposition temperature, material for the buffer/protective layer and annealing temperature. Such value of coercivity is among the highest found in literature for thin films of SmCo.