Comparison of the mechanical properties of amorphous FeSiB and FeGaSiB films

As technology gets smaller, the need to understand how the mechanical as well as functional properties of thin magnetic films change as a function of thickness and substrate is required. This then allows for better material selection for applications, as thin amorphous and nanocrystalline magnetic films are used in micro-electromechanical systems (MEMS), such as actuators, field and strain sensors. This work used the nanoindentation technique to study the mechanical properties (hardness, Young’s modulus and yield strength) of amorphous FeGaSiB and FeSiB thin films to determine how the thickness, substrate and composition influence these properties. Along with understanding how the addition of Ga changed the amorphicity of the films with thickness. It was found that the Young’s Modulus and hardness decreased by ∼15% with the addition of Ga, plus the films were less elastic compared to the FeSiB films. The yield strength was 30% higher for the films grown on glass compared to silicon, while the hardness and Young’s modulus of both FeSiB and FeGaSiB films increased with decreasing film thickness. Further, these results helped to gain understanding on the role of film thickness to the amorphicity of the film.