One of the reasons for selecting Meridiani Planum as one of the two landing sites for the MER (Mars Exploration Rover) mission was the detection of a hematite signature by the TES (Thermal Emission Spectrometer) instrument onboard MGS (Mars Global surveyor) [1]. The presence of hematite at Meridiani has since been confirmed by instruments of the Athena Science Payload of the Opportunity MER rov...

Iron oxides in nature take on different forms. „The most common iron oxide is hematite, Fe2O3, which is the end product of many geological processes and the main source of iron for our civilization,“ explains Bykova. During the past five years, however, scientists have discovered other iron oxides like Fe4O5, Fe5O6, and Fe13O19 that form at high pressures and temperatures. Investigating the beh...

Oxidation of metals usually results in the formation of an oxide nanostructure with poorly controlled growth morphologies. By employing a simple mechanical approach that uses sandblasting to modify the surface roughness of iron substrates, we demonstrate that the morphologies of hematite (α-Fe2O3) nanostructures varying from the growth of one-dimensional nanowires to two-dimensional nanoblades ...

due to the abundance of the non-coking coal and limitations as well as the high costs of the natural gas, the presentstudy examined the direct reduction of hematite (iron oxide) ore in the temperature range of 800-1000 °c by thenon-coking coal volatiles. approximately, 74.9% of the total amounts of volatiles and gases exit the coal up to800°c. the onset temperature to exit volatiles from the no...

mold powders used in the continuous casting of steel contain the harmful caf2 as a main substance developing toxic gases such as sif4 and hf at elevated temperatures. in this study, three samples of i1, i2 and i3, which contained gypsum free portland cement clinker with different percentages of fe2o3 (5.68, 6.83, 8.02 ) and f- (2.09, 1.06, 0), were prepared and their main characteristics were c...

The oxygen content of the atmosphere is thought to have increased in two steps: the Paleoproterozoic Great Oxidation Event and the Neoproterozoic Oxidation Event. The younger event is still a matter of debate (Och and Shields-Zhou, 2012). Macouin et al. (2015) suggest that it may have been triggered by volcanic degassing from unusually oxidized magmas occurring in a subduction ring surrounding ...

Introduction. Lane et al. [1] and Christensen et al. [2] conclude that 1996 Global Surveyor Thermal Emission Spectrometer (TES, ~1700–200 cm) spectra of regions in Sinus Meridiani are consistent with hematite. The observed band strengths are inconsistent with unconsolidated, nanophase hematite dust, but are consistent with laboratory spectra of pure, coarselyparticulate hematite. We seek to ext...

Hematite (α-Fe2O3) persists as a promising candidate for photoelectrochemical water splitting, but a slow oxygen evolution reaction (OER) at its surfaces remains a limitation. Here we extend a series of studies that examine pH-dependent surface potentials and electron-transfer properties of effectively perfect low-index crystal faces of hematite in contact with simple electrolyte. Zero-resistan...

Spherical and quite monodisperse particles (average diameter 60 ( 7 nm) of hematite (R-Fe2O3) were synthesized and then covered with a shell of yttrium oxide of variable thickness. A surface thermodynamic study was carried out for these core/shell colloidal particles, using two experimental techniques: contact angle measurements of selected liquids on glass slides uniformly covered by the mater...

Iron oxide nanoparticles are widely prevalent in our aqueous environment (e.g., streams, seawater, hydrothermal vents). Their aggregation and crystal growth depend on their chemical surroundings, for instance just a change in pH or salt concentration can greatly affect this. In turn this influences their properties, mobility, fate, and environmental impact. We studied the growth of α-Fe2O3 (hem...