Structural morphology of crystals with the barite (BaSO4) structure: A revision and extension

Hartman, P.; Strom, C.S.

doi:10.1016/0022-0248(89)90233-9

Cited by 63 publications

(59 citation statements)

References 27 publications

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“…EDX analyses of the newly-formed crystals showed that they are mainly composed of S, 0 and Pb. Both the composition and the morphology (Hartman and Strom, 1989) of these crystals are consistent with those of anglesite, which was confirmed by XRD analysis carried out on the surface of the gypsum substrate.…”

Section: Sem Observationssupporting

confidence: 72%

Interaction of gypsum with lead in aqueous solutions

Astilleros

Γοδελίτσας

Rodríguez-Blanco

et al. 2010

Applied Geochemistry

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Section: Sem Observationssupporting

confidence: 72%

Interaction of gypsum with lead in aqueous solutions

Astilleros

Γοδελίτσας

Rodríguez-Blanco

et al. 2010

Applied Geochemistry

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“…Our measure ments show that for carbonate concentrations below 0.05 mM (i.e. carbonate concentration for which no growth inhibition is detected) the height of the two-dimensional islands remains constant, with a value of 3.5 A (the height of the elementary growth layer for pure barite {DO l) faces [26]). However, above the threshold carbonate concentra tion ([CO;-] � 0.05 mM), inhibition occurs and simulta neously the height of (001) two-dimensional islands decreases with the carbonate concentration in the aqueous solution (Fig.…”

Section: Inhibition Of Growth On Barite {�Ol} and {210}mentioning

confidence: 78%

The effect of CO32- on the growth of barite {0 0 1} and {2 1 0} surfaces: An AFM study

et al. 2006

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The growth of barite {O 0 I } and {2 I O} faces from aqueous solutions moderately supersaturated with respect to barite ({Jbarite ;::: :; 12 for experiments on {O 01} surfaces and {Jbarile ;::: :; 7 for experiments on {21 O} surfaces) and bearing different concentrations of carbonate has been studied in situ using an atomic force microscope (AFM). Nanoscopic observations show that, above a certain carbonate concen tration threshold in the aqueous solution, the advancement of mono layers (�3.5A in height) on barite {0 01} and (210} surfaces is strongly inhibited. However, inhibition never affects the growth of the first monolayer, whose growth rate increases in the presence of carbonate. In contrast, the second monolayer growth rate decreases as the concentration of carbonate in the solution increases. For high carbonate concentrations in the solution, growth stops after the formation of the first monolayer. While on barite {O 0 I } faces, the for mation of a second monolayer does not occur for carbonate concentrations higher than 0. 2 mM, on barite (21 O} faces the complete inhibition of the second monolayer is observed for carbonate concentrations higher than 0.05 mM. Once growth on {O 0 I} or {21 O} faces is completely inhibited, i. e. such surfaces are in the "dead zone", growth can be recovered by increasing supersaturation. In order to study the recovery behaviour of barite {O 0 I } and (2 I O} faces from the "dead zone", an additional series of AFM experiments have been conducted. In these experiments, carbonate-free aqueous solutions with increasing supersaturations with respect to barite were passed over (00 I} and (21 O} surfaces previously "poisoned" with carbonate. Our experimental results show that the recovery of growth on barite {O O I} faces requires an important increase of the solution supersaturation. In contrast, the recovery of barite {21 O} surface growth does not require any supersaturation increase, but spontaneously occurs in a few minutes. Our observations of inhibition and growth recovery on barite surfaces at a nano-scale are discussed and compared with the descriptions given by the classical crystal growth inhibition models.

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“…The struc tural description of barite (001) faces given by the Periodic Bond Chain (PBC) theory provides an adequate starting point for discussing the char acteristics of the epitaxial growth of celestite on barite (001) surfaces. According to Hartman and Strom [22] elementary growth layers for barite (001) face have half a unit cell height, i.e. slices dg� = 3.5 A.…”

Section: Qgu)mentioning

confidence: 99%

Epitaxial growth of celestite on barite (0 0 1) face at a molecular scale

et al. 2005

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In situ AFM experiments have been conducted in order to obtain information about kinetics of celestite epitaxial growth on barite. Growth has been promoted by passing aqueous solutions supersaturated with respect to celestite over freshly cleaved barite (00 I) surfaces. Solution supersaturation, {3celestite, was varied from I to 45.7 ({3celestite = a(Sr2+). a(SO�-)IKs p , cel)' At supersaturations below 10 neither two-dimensional nucleation neither step advancement are observed on barite (001 ) surfaces. However, once the two-dimensional nucleation barrier is overcome ({3celes tite> 10), nuclei preferentially form on cleavage steps parallel to [1 00], [1 10] and [120] directions and more scarcely on terraces. The subsequent growth of two-dimensional nuclei leads to the development of celestite "islands". Their morphology is defined by (00 I) face and {21 O} and {lOO} forms and can be explained on the basis of PBC theory, The coalescence of such islands results in the formation of a homogeneous SrS04layer. Growth rates along [00 I] direc tion have been measured for the whole supersaturation range. The growth rate equation for "Birth and Spread" crystal growth mechanism has been successfully fitted to our experimental data. The fitting process has provided basic growth parameters in a good agreement with theoretical ones. Both the high transitional supersaturation required for two dimensional nucleation and the high interfacial energy value obtained from the fitting of the "Birth and Spread" equa tion (O'ociibar = 0.137 J 1m2) indicate low affinity of SrS04 growth units for barite (00 I) faces. This is consistent with the relative high mismatch between celestite and barite structure, The behaviour of the epitaxial growth described in this work can help to interpret the oscillatory zoning frequently occurring in both natural and synthetic crystals of the BaxSrl_xS04 solid solution.

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Structural morphology of crystals with the barite (BaSO4) structure: A revision and extension

Cited by 63 publications

References 27 publications

Interaction of gypsum with lead in aqueous solutions

Interaction of gypsum with lead in aqueous solutions

The effect of CO32- on the growth of barite {0 0 1} and {2 1 0} surfaces: An AFM study

Epitaxial growth of celestite on barite (0 0 1) face at a molecular scale

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