Investigations on structural morphological and magnetic properties of electrodeposited nanocrystalline nifep thin films

Abstract

In recent times magnetic materials have become the promising and prospective materials for device applications in Micro Electro Mechanical System (MEMS) and Nano Electro Mechanical Systems (NEMS) which includes hard disk magnetic recording heads, magnetic micro motors, inductors, sensors, high density recording media, micro relays and micro actuators etc., For these applications, the soft magnetic thin films are particularly utilized because of their high saturation magnetization, higher permeability, lower coercivity, near zero magnetostriction, high electrical resistance and lower hysteresis loss. In the present work, NiFeP based soft magnetic thin films are chosen to be investigated for the production of MEMS devices as they have good soft magnetic nature but their applications in the field of MEMS are restricted due to their limited corrosion resistance, strength and hardness properties. In order to enhance the corrosion resistance and magnetic nature, elements like Mo, Mn, W, Cr, P etc. are added to NiFe. Among these, phosphorous addition is expected to give a better corrosion resistance and wear resistance which in turn is expected to enhance the magnetic behaviour of the films. However, deposition of these films require special care, since contamination and variation of composition is expected to have an adverse effect on the magnetic properties of the films. Though NiFe alloy thin films can be synthesised by various methods, including sputtering, evaporation, and electro deposition, with a great demand to enhance the magnetic behavior, the most suitable method for synthesizing NiFe based nano crystalline ferromagnetic thin films is the electroplating method due its advantages like low cost, large scale production, minimum wastage of chemicals, better efficiency etc. newline