Investigation on tungsten w and phosphorus p co deposited nanostructured nickel based alloy thin films for mems applications

Abstract

In recent years Ni-based alloy materials are potentially used in Micro Electro Mechanical Systems (MEMS) and Nano Electro Mechanical Systems (NEMS) such as magnetic micro motors, sensors, actuators, micro transformers, switches, magnetic recording heads etc . One of the widely preferred soft magnetic materials for MEMS and NEMS devices is NiFe alloys. The low coercivity, high saturation magnetization, high permeability, low magnetostriction, and low hysteresis loss, offered by the NiFe alloy soft magnetic materials make the effective integration of this material in MEMS and NEMS devices. But the application of NiFe alloy soft magnetic thin film is limited due to the mechanical strength, hardness and corrosion resistance. Hence enhancing the mechanical properties of NiFe alloy thin films or exploring the alternate Ni based alloy to NiFe is very important for MEMS and NEMS devices. newlineThe refractory metal elements such as niobium, chromium, molybdenum, tantalum, tungsten, and rhenium have very high melting points of gt2000 and#730;C (Lance L.Snead et al. 2019). The properties of refractory metal elements include high hardness, high strength, good ductility, high toughness, good corrosion resistance, and very high thermal shock resistance. The recent research focuses on alloying the refractory metal elements with Ni to enhance the mechanical properties. Alloying chromium with nickel improves the mechanical properties such as very high hardness, excellent wear resistance, low coefficient of friction, and excellent corrosion resistance. Even though NiCr plating provides very good mechanical properties, Chromium in hexavalent state Cr(VI) is a carcinogen for human and animals. newlineIn this research work, the effort has been taken to improve the mechanical properties such as hardness and corrosion resistance of the Ni-based alloy thin films without affecting the soft magnetic nature.