Studying The Effect of Growth Parameters On Magnetostrictive Amorphous Thin Films And Study The Mechanical Properties By Nanoindentation.

Magnetostrictive amorphous thin films are being developed for a wide range of MEMS applications, including strain sensors and magnetostrictive actuators. To achieve the sensitivities required for these applications the magnetic films used have to possess a large magnetostriction constant (>50ppm) and a small anisotropy field (<10kA/m). The work presented here investigates magnetostrictive amorphous thin films, including FeSiB and FeGaSiB films, to achieve these required parameters. A co-sputtering – evaporation deposition technique was used to fabricate the films, which allows control of the Ga percentage within the films. The films were grown on the silicon (100) substrates. The effect of changing the growth parameters including the sputtering power, the chamber pressure and the Ga evaporation rate were studied to determine their influence on the structural, magnetic and magnetostriction properties of these amorphous films. While the magnetic properties (coercive and anisotropy field and magnetostriction constant) were measured on a Magneto-optical Kerr effect (MOKE) magnetometer. A VSM was used to measure the magnetisation of films. A bending tool was used to strain the films via the Villari Effect. The mechanical properties were studied by nanoindentation technique.