RT Journal Article
T1 Trade-off analysis of C12A7: e-deposition techniques applied to Low Work Function Tethers
A1 Fabian-Plaza, Jose
A1 Meiro, Gerardo
A1 Post, Angel
A1 Perez-Casero, Rafael
A1 Palomares, F. Javier
A1 Tejedor Jorge, Paloma
A1 Naghdi, Samira
A1 Lumbier Álvarez, Alejandro
A1 Sánchez Arriaga, Gonzalo
AB Due to its extraordinary properties, the C12A7:e− electride has been suggested in the past as one of the most promising materials for coating Low Work-function Tethers (LWTs). Such subclass of electrodynamic tether, made of a conductive substrate coated with materials that enhance the electron emission through the thermionic and photoelectric effects, would constitute a fully passive and consumable-free device for deorbiting space debris from Low Earth Orbit. This work presents experimental results on the manufacturing and testing of small tape-like LWT samples, which is the relevant geometry for electrodynamic tether applications. After preparing C12A7:e− targets under specific and controlled conditions, thin titanium foils have been coated with the C12A7:e− electride by using two different physical vapor deposition techniques: magnetron sputtering (MS) and pulsed laser deposition (PLD). In the case of MS, important difficulties and defects were found, including target damage, poor growth rate, and oxidation and changes in the composition of the coating. However, the performance on the PLD coating was radically different. First, Rutherford backscattering spectrometry confirmed that the composition of the thin film with the PLD coincides with that of the target. Second, X-ray photoelectron spectroscopy and thermionic emission experiments showed that the work function of the LWT sample is 2.6 ± 0.1 eV. Therefore, the trade-off analysis indicates that PLD can be used to manufacture LWT samples with work function close to the one of the bulk C12A7:e− (2.4 eV). Nevertheless, its application as passive cathode in electrodynamic tethers still requires further research activities.
PB Elsevier
SN 0094-5765
YR 2020
FD 2020-12
LK https://hdl.handle.net/10016/32545
UL https://hdl.handle.net/10016/32545
LA eng
NO This work was supported by Agencia Estatal de Investigación (Ministerio de Ciencia, Innovación y Universidades of Spain) under the project ESP2017-82092-ERC (AEI). Work by JFP and AP has been supported by the Centro para el Desarrollo Tecnológico e Industrial (CDTI) under the project IDI-20171255. FJP and PT acknowledge the support by ATD under project contract ICMM-CSIC #010101170104. SN work is supported by Comunidad de Madrid (Spain) under the Grant 2018/T2IND/11352. GSA work is supported by the Ministerio de Ciencia, Innovación y Universidades of Spain under the Grant RYC-2014-15357.
DS e-Archivo
RD 1 sept. 2024