Final published version
Research output: Contribution to conference - Without ISBN/ISSN › Conference paper › peer-review
Research output: Contribution to conference - Without ISBN/ISSN › Conference paper › peer-review
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TY - CONF
T1 - Fluoride-free wet-chemical preparation of oxide single crystal surfaces
T2 - 66th Annual Meeting of the Austrian Physical Society
AU - Mertens, Stijn F. L.
AU - Müllner, Matthias
AU - Balajka, Jan
AU - Schmid, Michael
AU - Diebold, Ulrike
N1 - Conference code: 66
PY - 2016/9/26
Y1 - 2016/9/26
N2 - The ultimate goal to perform surface science studies under technologically relevant conditions includes wet-chemical methods to preparewell-defined oxide surfaces [1]. The most widely practised approachis hydrofluoric acid etching, even though this chemical poses serioushealth risks and may inadvertently dope the surface with fluorine, anefficient electron donor [2].Here, we present a rational yet versatile wet-chemical alternative tolengthy sputtering–annealing cycles in ultrahigh vacuum for preparingsingle crystal oxide samples for surface science investigations. The method does not require hydrofluoric acid, is environmentally benign andis demonstrated on rutile TiO2 (110), rutile TiO2 (011) and SrTiO3 (100),but may have much wider application potential, also for surfaces thatare quickly destroyed by acids.The procedure consists of (i) ultrasonication in the presence of a dispersing agent to remove polishing debris; (ii) thermal annealing to produceequilibrium-shaped steps and terraces determined by the crystalmiscut; and (iii) oxidative cleaning in an alkaline mixture to removeadsorbed organic contaminants from the surface. Each of the stepsis optimised based on AFM and characterisation in ultrahigh vacuum,including by LEED and XPS. Following this wet-chemical preparation, wedemonstrate atomically resolved electrochemical scanning tunnellingmicroscopy on TiO2 (110), on a sample that was never treated by sputtering–annealing.
AB - The ultimate goal to perform surface science studies under technologically relevant conditions includes wet-chemical methods to preparewell-defined oxide surfaces [1]. The most widely practised approachis hydrofluoric acid etching, even though this chemical poses serioushealth risks and may inadvertently dope the surface with fluorine, anefficient electron donor [2].Here, we present a rational yet versatile wet-chemical alternative tolengthy sputtering–annealing cycles in ultrahigh vacuum for preparingsingle crystal oxide samples for surface science investigations. The method does not require hydrofluoric acid, is environmentally benign andis demonstrated on rutile TiO2 (110), rutile TiO2 (011) and SrTiO3 (100),but may have much wider application potential, also for surfaces thatare quickly destroyed by acids.The procedure consists of (i) ultrasonication in the presence of a dispersing agent to remove polishing debris; (ii) thermal annealing to produceequilibrium-shaped steps and terraces determined by the crystalmiscut; and (iii) oxidative cleaning in an alkaline mixture to removeadsorbed organic contaminants from the surface. Each of the stepsis optimised based on AFM and characterisation in ultrahigh vacuum,including by LEED and XPS. Following this wet-chemical preparation, wedemonstrate atomically resolved electrochemical scanning tunnellingmicroscopy on TiO2 (110), on a sample that was never treated by sputtering–annealing.
M3 - Conference paper
SP - 195
Y2 - 27 September 2016 through 29 September 2016
ER -