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Sebastiano Vasi

Publications and source records attributed to Sebastiano Vasi.

2 recordsLinked to original sources

Morphological Evolution of Nickel-Fullerene Thin Film Mixtures

Hybrid systems consisting of metal-fullerene composites exhibit intriguing properties but often suffer from thermal instability. With proper control, such instability can be harnessed to enable the formation of sophisticated nanostructures with nanometric precision. These self-organization phenomena are not limited to thermal stimulation alone but can also be triggered by other external stimuli. In this work, we investigate the morphological evolution of thin films composed of evaporated C60 and sputtered nickel mixtures, focusing on how external stimuli influence both their structural and electrical properties. Thin films were prepared under controlled deposition conditions, and their surface morphology was analyzed using advanced characterization techniques. Progressive changes in film morphology were observed as a function of composition and external treatment, highlighting the interplay between metallic and molecular components. In particular, it was observed that, due to the annealing treatment, the sample undergoes strong phase separation, with the formation of structures tens of microns in diameter and an increase in electrical resistance, exhibiting insulating behavior. These findings provide insights into the mechanisms governing hybrid thin film formation and suggest potential applications in electronic, optoelectronic, and energy-related devices.

cond-mat.mtrl-sci

Hybrid films of Co - C60 preparation and changes induced by external stimuli

In this work, we report on the study on organic-metal hybrid systems, in particular Co-C60 fullerene thin films. This study mainly focused on the investigation of the morphological and structural evolution of the film surface after various external stimuli designed to provide energy to the system. For film growth, we adopted an innovative approach, combining ion-beam sputtering of a pure metal target with thermal evaporation of C60 in a co-deposition setup. The films underwent a series of treatments to induce modifications. Laser and ion irradiations were performed using a pulsed laser, a continuous Ar beam, and a pulsed C beam. In addition, thermal annealing in vacuum was performed to examine the long-term effects of temperature. The composition of deposited film was investigated using Ion Beam Analysis, the morphology and the structure, and the effects of treatments on the films were studied using SEM and TEM microscopies and Raman spectroscopy. Changes in electrical resistance were also measured to explore potential applications of these films after treatment.

cond-mat.mtrl-sci