TY  - JOUR
VL  - 37
A1  - Ali, A.M.
A1  - Padmanabhan, E.
A1  - Baioumy, H.
JF  - Acta Geochimica
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045133022&doi=10.1007%2fs11631-018-0267-6&partnerID=40&md5=630e9a33a1d029e903c311193c126eb7
Y1  - 2018///
ID  - scholars9565
KW  - Alkalinity; Characterization; Chemical bonds; Crystallite size; Field emission microscopes; Fourier transform infrared spectroscopy; High resolution transmission electron microscopy; Hydraulic servomechanisms; Iron oxides; Needles; Quartz; Scanning electron microscopy; Sediments; Silicates; Spectroscopic analysis; Transmission electron microscopy; X ray diffraction
KW  -  Chemical environment; Field emission scanning electron microscopy; Fourier transform infra red (FTIR) spectroscopy; FTIR spectroscopy; Goethite; Microscopic characterization; Spectroscopic studies; Twinned goethite
KW  -  Crystal structure
KW  -  crystal chemistry; crystal structure; FTIR spectroscopy; goethite; lattice dynamics; microscopy; quartz; scanning electron microscopy; silica; spectral analysis; transmission electron microscopy; twinning
N2  - Quartz and iron (hydr)oxide are reactive surface phases that are often associated with one another in soils and sediments. Despite the several studies on the coating of quartz with iron oxides, the reactivity of dissolved species (Si) leached from quartz with iron (hydr)oxides has received limited attention. In this study, goethite synthesized on quartz substrates were characterized using field emission scanning electron microscopy, X-ray diffraction (XRD), transmission electron microscopy, and Fourier-transform infrared (FT-IR) spectroscopy. The SEM characterization revealed that bundles of thin parallel aligned goethite rods were formed at pH > 10, while large pseudohexagonal crystals of twinned goethite needles were synthesized at pH â?¤ 10 after dehydration and hydration in the alkaline media. TEM analysis showed expanded and distorted lattice spacing of the crystal structure of iron (hydr)oxide due to silica incorporation. The characterization showed that silica increased the crystallite size of the goethite and transformed its acicular texture to a larger, twinned needle structure. FT-IR and XRD analyses revealed band shifts in crystal bonds as well as new bond formations, which indicate the presence of changes in the chemical environment of Feâ??O and Siâ??O bonds. Thus, the presence of sorbed silicates modifies the crystal and lattice structure of goethite. © 2018, Science Press, Institute of Geochemistry, CAS and Springer-Verlag GmbH Germany, part of Springer Nature.
IS  - 6
EP  - 921
PB  - Science Press
SN  - 20960956
SP  - 911
TI  - Incorporation of silica into the goethite structure: a microscopic and spectroscopic study
N1  - cited By 4
AV  - none
ER  -