Crystalizing metallic compound film by ion irradiation in plasma

Summary form only given. Micro machines are expected in advanced medical instruments for micro surgery. Typical materials for the actuators in micro machines are shape memory alloys like nickel titanium (TiNi) and piezoelectric compounds like lead zirconate titanate (PZT). For medical application in a future the materials will be required to be deposited directly on surfaces of plastics as thin film in a crystalline structure, since most medical instruments such as catheters for blood vessel surgery are made of polymeric plastics. Then, the film will be finished into some actuators. However, this process had some technical difficulties to be resolved. Since compound film as deposited by physical deposition like magnetron sputtering was usually amorphous, the film had been crystallized traditionally by thermal annealing over 800 K in order to have ferroic properties such as shape memory effect or piezoelectric effect¹. But the thermal annealing is actually hard to be applied to the above-mentioned medical instruments in a future, since most plastics cannot withstand the higher temperatures than 500 K.