Ricerc@Sapienza

Electric Solar sail (ESAIL) tethers may be subjected to barrage of incident charged particles, high energy photons and strong vibrations, depending on their working mechanism. Atomic Layer Deposition (ALD) technique can produce light-weight, conformal and defect-free coatings that can protect the metallic tethers from many anticipated harsh space effects. In addition to this, the coatings may be used to steer the equilibrium temperature of the tethers, especially when used in the deep solar system.

In this work, solid-liquid equilibria of the pseudo-binary system ThO2-ZrO2 are investigated. A series of different molar ratios (80:20, 60:40, 40:60, and 20:80 ThO2:ZrO2)of ThO2 and ZrO2 were synthesised at JRC-Karlsruhe using an external sol-gel method. The XRD data of samples sintered at 1650 °C show two-phase behaviour throughout the range of compositions with small solubility (<5%)of ZrO2 in ThO2 and limited solubility of ThO2 in ZrO2.

TiO2-SiO2 mixed oxides have been prepared by the sol–gel technique from tetrabutyl orthotitanate and tetraethyl orthosilicate. The prepared materials were characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, nitrogen physisorption, Fourier-transform infrared spectroscopy (FT-IR) and x-ray photoelectron spectroscopy (XPS). The results indicate that the TiO2-SiO2 mixed oxides have a large surface area and a nanoscale size. FT-IR spectra show that Ti atoms are bonded to silica by oxygen bridging atoms in Ti-O-Si bonds.