Nanostructured magnetic CoPt thin films synthesis using dense plasma focus device operating at sub-kilojoule range

Abstract

A repetitive NX2 dense plasma focus (DPF) device, operating at a low voltage of 8 kV with a stored energy of capacitor bank in the sub-kilojoule range (∼880 J), was successfully used to deposit nanostructured magnetic CoPt thin films. The samples were synthesized at different filling hydrogen gas pressures and using different numbers of plasma focus deposition shots. The size of agglomerates/nanoparticles and the thickness of the CoPt thin films depend strongly on the filling gas pressure and the number of plasma focus deposition shots; hence it provides a possibility to control the CoPt agglomerates/nanoparticles size and the deposition rate by simply changing the operating parameters of the DPF system. The typical deposition rate of nanostructured CoPt thin film in the DPF device is much higher as compared with that of conventional PLD. The as-deposited CoPt nanoparticles are in the magnetically soft fcc phase and an annealing temperature of about 600 °C is required for phase transition to the magnetically hard fct phase, which may find possible applications in high density data storage.