Positron annihilation study of cavities in black Au films

14th International Workshop on Slow Positron Beam Techniques & Applications

Melikhova, O.^1 ; íek, J.^1 ; Hruka, P.^1 ; Vlek, M.^1 ; Procházka, I.^1 ; Anwand, W.^2 ; Novotný, M.^3 ; Bulí, J.^3

Faculty of Mathematics and Physics, Charles University, V Holeovikách 2, Praha 8

18000, Czech Republic^1

Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf Bautzner Landstr. 400, Dresden

01328, Germany^2

Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, Prague 8

182 21, Czech Republic^3

关键词: Au film;    High reflectivity;    Multiple reflections;    Nano-structured;    Porous morphology;    Sub-surfaces;    Variable-energy positron annihilation spectroscopies;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/791/1/012018/pdf
DOI  :  10.1088/1742-6596/791/1/012018

来源: IOP

【 摘 要 】

Defects in a black Au film were studied using variable energy positron annihilation spectroscopy. Black Au films exhibit porous morphology similar to cauliflower. This type of structure enhances the optical absorption due to a multiple reflections in the micro-cavities. A nanostructured black Au film was compared with conventional smooth Au films with high reflectivity. The black Au film exhibited a remarkably enhanced S-parameter in sub-surface region. This is caused by a narrow para-Positronium contribution to the annihilation peak.