Water ordering and surface relaxations at the hematite (110)–water interface

Structure and oxidation state of hematite surfaces reacted with aqueous Fe(II) at acidic and neutral pH

“…The 1 cm 2 crystals were cleaned prior to use following previously described methods . Auger electron spectroscopy showed only Fe, O and adventitious C on the surfaces of the as-received crystals (Catalano et al, 2009). Single crystals displaying the (0 0 1) surface were prepared and pre-characterized as described by Yanina and Rosso (2008).…”

“…Each dataset was fit with a structural model coupled to sample-specific extrinsic parameters including the attenuation of the X-ray beam through the containment material (Fenter, 2002), surface roughness (Robinson, 1986), and an intensity scale factor to account for imperfect normalization of the data to the incident beam flux. The structural models employed were based on those determined in previous studies of hematite-water interface structures (Trainor et al, 2004;Catalano et al, 2007aCatalano et al, , 2009. Further details regarding the structural models employed in the individual analyses are discussed in Section 3.1.…”

“…As other features in the XR were generally unchanged (e.g., relative intensities of the midzones, overall shape of the XR profile), this suggests that the atomic arrangement on the terrace surfaces has not been affected by Fe(II) reaction. Attempts were made to fit these XR data with the structural model obtained for the unreacted surface in deionized water (Catalano et al, 2009) but without the layered water profile and multiple adsorbed water sites specific to the interfacial structure in contact with water because the samples were examined under dry conditions. Instead, a single oxygen layer was employed to describe the density from a possible layer of adsorbed water and/or adventitious carbon (X-ray scattering by C and O is similar).…”

Fugitive Dust Emissions from a Coal-, Iron Ore- and Hydrated Alumina Stockpile

“…When hematite is watered and left to dry a uniform crust develops over the sample. The crust can be destroyed by mechanical action or by re-watering the iron ore. As found out previously, the first two water layers near the hematite surface are highly ordered, and effectively are adsorbed to the surface through hydrogen bonding and further from the surface, water still displays some ordering in the form of layering (Catalano et al, 2009). Different hematite particles are bound between themselves by the interaction of these water layers, which are not removed in the process of drying.…”

Mineral-Aqueous Solution Interfaces and Their Impact on the Environment

“…Direct evidence for the structured nature of water at mineral-water interfaces comes from many recent X-ray reflectivity, CTR diffraction, or RAXR studies of rutile (110) (Fenter et al ., 2000a), a-Al 2 O 3 (0001) (Eng et al ., 2000;Catalano, 2011), a-Al 2 O 3 (11-20) (Catalano, 2010), a-Fe 2 O 3 (0001) (Catalano, 2011), a-Fe 2 O 3 (110) (Catalano et al ., 2009), a-Fe 2 O 3 (012) , a-FeOOH(110) (Ghose et al ., 2008), and muscovite(001) (Miranda et al ., 1998;Cheng et al, 2001) . Other studies of the nature of interfacial water using non-linear optical methods include quartz(001)-water interfaces (Ostroverkhov et al ., 2005), water-vapour interfaces involving acidic and basic solutions (Tian et al ., 2008), and interfacial water around haematite nanoparticles (Spagnoli et al ., 2009) .…”