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JournalISSN: 0342-1791

Physics and Chemistry of Minerals 

Springer Science+Business Media
About: Physics and Chemistry of Minerals is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Raman spectroscopy & Phase transition. It has an ISSN identifier of 0342-1791. Over the lifetime, 1732 publications have been published receiving 48962 citations. The journal is also known as: Phys Chem Minerals.


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Journal ArticleDOI
TL;DR: In this paper, the authors examined the geometry of 149 oxide and 80 sulfide binary and ternary spinels from the standpoint of ionic radius and electronegativity, and found that the mean ionic radii of the octahedral and tetrahedral cations, taken together, account for 96.9 and 90.5% of the variation in the unit cell parameters of the oxides and sulfides, respectively.
Abstract: Systematic trends in the geometry of 149 oxide and 80 sulfide binary and ternary spinels have been examined from the standpoint of ionic radius and electronegativity. The mean ionic radii of the octahedral and tetrahedral cations, taken together, account for 96.9 and 90.5% of the variation in the unit cell parameter, a, of the oxides and sulfides, respectively, with the octahedral cation exerting by far the dominant influence in sulfides. The mean electronegativity of the octahedral cation exerts an additional, but small, influence on the cell edge of the sulfides. The equation a=(8/3√d)d tet+(8/3)d oct, where d tet and d oct are the tetrahedral and octahedral bond lengths obained from the sum of the ionic radii, accounts for 96.7 and 83.2% of the variation in a in the oxides and sulfides, respectively, again testifying to the applicability of the hard-sphere ionic model in the case of the spinel structure. Comparison of observed and calculated u values for 94 spinels indicates that up to 40% of the experimentally measured anion coordinates may be significantly in error. In addition to these compounds, u values are given for 52 spinels for which no data have previously been determined. Diagrams are presented for the rapid interpretation of the internal consistency of published data and the prediction of the structural parameters of hypothetical or partially studied spinels.

652 citations

Journal ArticleDOI
TL;DR: The spectral peak binding energies of Ni metal, NiS, and NiAs (all conductors) span a range of about 0.5ÕeV and are, consequently, insensitive to formal Ni oxidation state and the nature of the ligand to which Ni is bonded, relative to other metals (e.g., Fe) as discussed by the authors.
Abstract: Ni2p3/2 X-ray photoelectron spectral peak binding energies of Ni metal, NiS, and NiAs (all conductors) span a range of about 0.5 eV and are, consequently, insensitive to formal Ni oxidation state and to the nature of the ligand to which Ni is bonded, relative to other metals (e.g., Fe). Ni2p3/2 peak structures and binding energies reflect two energetic contributions. The major contribution is that associated with the electrostatic field produced by ejection of the Ni(2p) photoelectron, the minor contribution is the relaxation energy associated with filling unoccupied, conduction band 3d9 and 4s Ni metal orbitals. These conduction band orbitals become localized on the Ni photoion (and sometimes filled) in response to the field created by the photoemission event. Because only the core Ni2p electron and nonbonding orbitals of predominantly metallic character are affected, the main peak of all three conductors are affected similarly, leading to similar Ni2p3/2 main peak binding energies. NiO, Ni(OH)2, and NiSO4 are insulators in which Ni is divalent and is bonded to oxygen. Although Ni is bonded to oxide in these phases, Ni2p binding energies differ substantially, and reflect primarily the nature of the ligand (O2−, OH−, SO4 2−) to which Ni is bonded. The influence of the ligand is the result of charge (electron) transfer from valence band bonding orbitals of dominantly ligand character, to unoccupied conduction band orbitals localized on Ni photoions. Relaxation energy resulting from charge transfer is acquired by the emitted photoelectron, thus Ni2p3/2 photopeak binding energies of these insulators reflect the nature of the ligand to which Ni is bonded. The Ni2p main peak binding energy of these conductors and insulators is a poor guide to Ni oxidation states. The Ni2p3/2 binding energies of insulators reflect, however, the nature of the ligand in the first coordination sphere of Ni. The intensity of the Doniach–Sunjic contribution to Ni2p XPS spectra of NiS and NiAs is dependent on the nature of the ligand. The Doniach–Sunjic contribution to ligand XPS core-level photopeaks (e.g., S2p of NiS and As3d of NiAs) has not been explained and is poorly understood.

498 citations

Journal ArticleDOI
TL;DR: In this article, the fundamental building blocks from which borate polyanions can be constructed are defined on the basis of the number n of boron atoms, and the fully hydrated polyanion is illustrated.
Abstract: The rules governing formation of hydrated borate polyanions that were proposed by C.L. Christ in 1960 are critically reviewed and new rules added on the basis of recent crystal structure determinations. Principles and classifications previously published by others are also critically reviewed briefly. The fundamental building blocks from which borate polyanions can be constructed are defined on the basis of the number n of boron atoms, and the fully hydrated polyanions are illustrated. Known structures are grouped accordingly, and a shorthand notation using n and symbols Δ = triangle, T = tetrahedron is introduced so that the polyanions can be easily characterized. For example, 3:Δ+2T describes [B3O3(OH)5]2−. Correct structural formulas are assigned borates with known structures whereas borates of unknown structure are grouped separately.

335 citations

Journal ArticleDOI
TL;DR: The infrared spectra of well characterized hydrotalcite-like compounds with M2+/M3+= 2/1 and M 2+/m3+= 3/1 chemical ratios indicate that octahedral cation ordering is only present for the 2 /1 composition as discussed by the authors.
Abstract: The infrared spectra of well characterized hydrotalcite-like compounds with M2+/M3+= 2/1 and M2+/M3+=3/1 chemical ratios indicate that octahedral cation ordering is only present for the 2/1 composition. For M2+/M3+ ratios greater than 2/1, the octahedral sheets are disordered although local cation order can be present through cation segregation. The order-disorder characteristics of these compounds can be explained by the total cation charge around any hydroxyl which cannot exceed seven units nor be lower than six. In addition, the infrared spectra suggest that the interlayer anions are symmetrically perturbed, the electrostatic interaction being greater for the 2/1 compositions.

304 citations

Journal ArticleDOI
TL;DR: In this article, the authors used synchrotron radiation to collect high-resolution Fe K absorption near-edge spectra of a suite of Fe minerals and compounds having a range of Fe environments.
Abstract: Synchrotron radiation has been used to collect high-resolution Fe K absorption near-edge spectra of a suite of Fe minerals and compounds having a range of Fe environments. These spectra, along with those of previous workers, indicate that the number, position, and intensity of near-edge features are characteristic of Fe valence and general site geometry. For example, the crest of the K-edge for Fe2+ in a six-coordinated site in the oxides studied is about 3 eV lower in energy than that for Fe3+ in a similar site. The K-edge crest for Fe3+ in a four-coordinated site is 1 to 2 eV lower than for Fe3+ in a regular site. The shape of the edge crest is sensitive to the details of first-neighbor bonding distances, tending to be broader in species with irregular Fe sites and varying in energy according to the average bond length. Comparison with Ca2+ and Zn2+ spectra from the literature is made and the applicability and utility of edge measurements discussed.

297 citations

Performance
Metrics
No. of papers from the Journal in previous years
YearPapers
202317
202253
202145
202051
201944
201838