Ioana-Laura Velicu

Structural and Magnetic Properties of FeCuNbSiB Thin Films Deposited by HiPIMS

Using high-power impulse magnetron sputtering (HiPIMS) technique, Fe73.5Cu1Nb3Si15.5B7 thin films with thickness between 40 and 700 nm were deposited. The influence of deposition conditions (deposition time and argon pressure) and of the annealing temperature on the structure and coercive magnetic field of the magnetic films was analyzed. In the as-deposited state, the coercive magnetic field presents a minimum at about 10 mtorr argon pressure. The X-ray diffraction studies show that in the as-deposited state, the samples are amorphous, while after annealing at temperatures between 400°C to 525°C, α-Fe(Si) grains start to nucleate, the grain size varying from 2 to 18 nm. The Curie temperature of as-deposited amorphous phase and the onset of the primary crystallization are 355°C and 460°C, respectively. The lowest coercive magnetic field was obtained after annealing at 475°C.

Pulsed Magnetron Sputtering: The Role of the Applied Power on W Coatings Properties

The interaction of low/high density transient plasma with tungsten (W) target was investigated via the sputtered material: in the gas phase, measuring the ion energy distribution function, and as deposited coatings, analyzing the compositional, structural, morphological, mechanical and tribological properties. The W target was sputtered in Ar atmosphere, at two different target power densities (instantaneous peak values of 0.2 and 3 kW/cm2), using a pulsed magnetron discharge. All obtained coatings were polycrystalline. A porous columnar structure was observed for the films deposited at low target power density, while denser-than-bulk films were obtained at high target power density. Comparing the high and low power modes, the W+ ion flux is seven times higher in the first case, while the deposition rate is three times higher in the second one.