Year: 2018
Type: conference-paper
Abstract: Little is known about the characteristics of hydrogen states in thin films of SnO 2 and Nb doped SnO 2 (NTO) and its influence on the electrical properties in these materials, which are promising candidates for metal-oxide supports in polymer electrolyte fuel cells.Here, we used low-energy muon spin rotation/relaxation (LE-µSR) to study hydrogen-like muonium (Mu) states between 5 K and 300 K in undoped and Nb doped SnO 2 films with Nb doping levels of 0.1% and 2%, respectively.The films were prepared by reactive DC magnetron sputtering on undoped Si substrates.Film thicknesses varied between 75 nm and 200 nm, and muons were implanted close to the surface at a mean depth of 10 nm, in the center of the films, and in some cases close to the NTO/Si interface.Our results of transverse-field and longitudinal-field µSR show striking similarities to recent bulk µSR measurements on various zirconia systems [Vieira et al., Phys.Rev. B 94, 115207 (2016)].This suggests that in the NTO systems the same Mu configurations exist which are the interstitial site with a deep, isotropic atomic Mu state, and, as the dominant fraction, the oxygen bound configuration with polaronic character.
Institution: Paul Scherrer Institute
Language: English
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
Funder: Paul Scherrer Institut
OpenAlex ID: W2789607192