Brownian thermal noise of thin-film coatings is a fundamental limit for high-precision experiments based on optical resonators such as gravitational-wave interferometers. Here we present the results of a research activity aiming to develop lower-noise ion-beam sputtered silicon nitride thin films compliant with the very stringent requirements on optical loss of gravitational-wave interferometers. In order to test the hypothesis of a correlation between the synthesis conditions of the films and their elemental comp…

Mass spectrometry measurements at high temperatures on amorphous Ta₂O₅, produced by Ion Beam Sputtering (IBS) and widely used for the high reflective coatings of the mirrors of gravitational-wave detectors, detect a release of argon around 1000 K. This process is thermally activated and the corresponding activation energy is 410 ± 60 kJ/mol. X-Ray Diffraction (XRD) measurements indicate that in the same range of temperature the crystallization of tantala takes place. Atomic Force Microscopy (…

The vapor pressures, pv, of three ionic compounds used as starting materials of deep eutectic systems, namely, tetrabutylammonium bromide (TBA-Br), tetrabutylammonium trifluoromethanesulfonate (TBA-TFO), and tetrabutylammonium bis(trifluoromethanesulfonyl)imide (TBA-NTF2), were measured using isothermal thermogravimetry. TBA-Br displays large values of pv, reaching ≈700 Pa at 170 °C. TBA-NTF2 is the less volatile liquid, with a vapor pressure of ≈1 Pa at 240 °C, while TBA-TFO has a slightly higher value of pv, of …

Abstract This work presents an in‐depth chemical and morphological investigation of the solid electrolyte interphase (SEI) formed on binder‐free silicon electrodes, which include both nanowire (Si‐NW) and amorphous (a‐Si) configurations, for next‐generation lithium‐ion battery systems. The study focuses on the first five galvanostatic cycles to capture the critical early‐stage SEI consolidation process, essential for understanding the interfacial phenomena that dictate long‐term performance. By employing innovativ…

Abstract Blistering is a phenomenon sometimes observed in sputtered-deposited thin films but seldom investigated in detail. Here, we consider the case of titania-doped germania (TGO)/silica multilayers deposited by ion beam sputtering. TGO is a candidate as high refractive index material in the Bragg mirrors for the next iteration of gravitational waves detectors. It needs to be annealed at 600 ∘ C for 100 h in order to reach the desired relaxation state. However under some growth conditions, in 52-layer TGO/silic…