Dopant incorporation into garnet solid solutions—a breakdown of Goldschmidt’s first ruleElectronic supplementary information (ESI) available: (1) comparison between observed and calculated structural parameters of the end-members pyrope and grossular. (2) GULP input file for configuration 1. See http://www.rsc.org/suppdata/cc/b2/b211249c/

2003 ◽  
pp. 786-787 ◽  
Author(s):  
W. van Westrenen ◽  
N. L. Allan ◽  
J. D. Blundy ◽  
M. Yu. Lavrentiev ◽  
B. R. Lucas ◽  
...  
2017 ◽  
Vol 81 (6) ◽  
pp. 1287-1302
Author(s):  
Ferdinando Bosi ◽  
Andrew G. Christy ◽  
Ulf Hålenius

AbstractFour specimens of the roméite-group minerals oxyplumboroméite and fluorcalcioroméite from the Långban Mn-Fe deposit in Central Sweden were structurally and chemically characterized by single-crystal X-ray diffraction, electron microprobe analysis and infrared spectroscopy. The data obtained and those on additional roméite samples from literature show that the main structural variations within the roméite group are related to variations in the content of Pb2+, which is incorporated into the roméite structure via the substitution Pb2+→A2+ where A2+ = Ca, Mn and Sr. Additionally, the cation occupancy at the six-fold coordinated B site, which is associated with the heterovalent substitution BFe3+ + Y☐→BSb5++YO2-, can strongly affect structural parameters.Chemical formulae of the roméite minerals group are discussed. According to crystal-chemical information, the species associated with the name ‘kenoplumboroméite’, hydroxycalcioroméite and fluorcalcioroméite most closely approximate end-member compositions Pb2(SbFe3+)O6☐, Ca2(Sb5+Ti) O6(OH) and (CaNa)Sb2O6F, respectively. However, in accord with pyrochlore nomenclature rules, their names correspond to multiple end-members and are best described by the general formulae: (Pb,#)2(Sb,#)2O6☐, (Ca,#)2(Sb,#)2O6(OH) and (Ca,#)Sb2(O,#)6F, where ‘#’ indicates an unspecified charge-balancing chemical substituent, including vacancies.


Author(s):  
Apuleyo Hernández-Pérez ◽  
Lauro Bucio ◽  
Alejandro Ibarra-Palos ◽  
María Elena Villafuerte-Castrejón

AbstractIn this work, a complete crystallochemical characterization of two solid solutions, which were founded in the binary end members system LaStructure refinements of Eu


2010 ◽  
Vol 74 (6) ◽  
pp. 969-978 ◽  
Author(s):  
I. E. Grey ◽  
W. G. Mumme ◽  
S. M. Neville ◽  
N. C. Wilson ◽  
W. D. Birch

AbstractSecondary phosphate assemblages from the Hagendorf Süd granitic pegmatite, containing the new Mn-Al phosphate mineral, nordgauite, have been characterized using scanning electron microscopy and electron microprobe analysis. Nordgauite nodules enclose crystals of the jahnsite—whiteite group of minerals, showing pronounced compositional zoning, spanning the full range of Fe/Al ratios between jahnsite and whiteite. The whiteite-rich members are F-bearing, whereas the jahnsite-rich members contain no F. Associated minerals include sphalerite, apatite, parascholzite, zwieselite-triplite solid solutions and a kingsmountite-related mineral. The average compositions of whiteite and jahnsite from different zoned regions correspond to jahnsite-(CaMnMn), whiteite-(CaMnMn) and the previously undescribed whiteite-(CaMnFe) end-members. Mo-Kα CCD intensity data were collected on a twinned crystal of the (CaMnMn)-dominant whiteite and refined in P2/a to wRobs = 0.064 for 1015 observed reflections.


2008 ◽  
Vol 23 (6) ◽  
pp. 1517-1521 ◽  
Author(s):  
M. Radovic ◽  
A. Ganguly ◽  
M.W. Barsoum

Herein we compare the lattice parameters, room temperature shear and Young’s moduli, and phonon thermal conductivities of Ti2AlC0.5N0.5 and Ti3Al(C0.5, N0.5)2 solid solutions with those of their end members, namely Ti2AlC, Ti2AlN, Ti3AlC2, and Ti4AlN2.9. In general, the replacement of C by N decreases the unit cell volumes and increases the elastic moduli and phonon thermal conductivities. The increase in the latter two properties, however, is sensitive to the concentrations of defects, most likely vacancies on one or more of the sublattices.


1982 ◽  
Vol 26 ◽  
pp. 119-128 ◽  
Author(s):  
Ronald C. Gehringer ◽  
Gregory J. McCarthy ◽  
R.G. Garvey ◽  
Deane K. Smith

Solid solutions are pervasive in minerals and in industrial inorganic materials. The analyst is often called upon to provide qualitative and quantitative X-ray phase analysis for specimens containing solid solutions when all that is available are Powder Diffraction File (PDF) data or commercial standards for the end members. In an earlier paper (1) we presented several examples of substantial errors in accuracy of quantitative analysis that can arise when the crystallinity and composition of the analyte standard do not match those of the analyte in the sample of interest. We recommended that to obtain more accurate quantitative analyses, one should determine the analyte composition (e.g., from XRF on grains seen in a SEM or from comparison of cell parameters with those of the end members) and synthesize an analyte standard with this composition and with a crystallinity approximating that of the analyte (e.g., as determined from peak breadth or α1/ α2 splitting).


2004 ◽  
Vol 19 (2) ◽  
pp. 488-495 ◽  
Author(s):  
H. Zheng ◽  
I.M. Reaney ◽  
G.D.C. Csete de Györgyfalva ◽  
R. Ubic ◽  
J. Yarwood ◽  
...  

Perovskite-structured solid solutions intended for use as microwave dielectric resonators were studied by Raman spectroscopy. Two distinct categories were investigated: (i) simple perovskite–simple perovskite solid solutions, that is, CaTiO3–SrTiO3 (CTST), CaTiO3–CaZrO3 (CTCZ), CaTiO3–NdAlO3 (CTNA), and CaTiO3–LaGaO3 (CTLG); and (ii) simple perovskite–complex perovskite solid solutions, such as CaTiO3–SrMg1/3Nb2/3O3 (CTSMN). In the latter category, the influence of A-site ion radius was also addressed by examining 0.5CaTiO3– 0.5LaMg1/2Ti1/2O3 (0.5CT–0.5LMT), 0.5SrTiO3 (ST)–0.5LMT, and 0.5BaTiO3 (BT)–0.5LMT. Raman data from the end members and solid solutions are compared, paying particular attention to F2g and A1g mode bands, often associated with ordering of B-site species.


2015 ◽  
Vol 34 (1) ◽  
pp. 125
Author(s):  
Tonci Balic-Zunic ◽  
Yves Moëlo ◽  
Ljiljana Karanović ◽  
Peter Berlepsch

Syntheses along the Tl<sub>5</sub>(As,Sb)<sub>13</sub>S<sub>22</sub> compositional line in the Tl<sub>2</sub>S-As<sub>2</sub>S<sub>3</sub>-Sb<sub>2</sub>S<sub>3</sub> phase system showed that the compositional range of rebulite extends from  Tl<sub>5</sub>As<sub>9.5</sub>Sb<sub>3.5</sub>S<sub>22</sub> to Tl<sub>5</sub>As<sub>7.75</sub>Sb<sub>5.25</sub>S<sub>22</sub>. The Sb-rich end-member is in equilibrium with jankovićite of ideal composition Tl<sub>5</sub>Sb<sub>7.5</sub>As<sub>5.5</sub>S<sub>22</sub>. It is considered to be the As-rich end-member of the jankovićite solid solution. The crystal structure analyses of crystals from the As and Sb end-members of rebulite show that the Sb/As substitution is present in Sb3, Sb4, Sb5, As1 and As2 structural sites. Of them, Sb3 is always Sb dominated whereas other four vary from As- to Sb-dominated over the range of the solid solution. The change of the structural topology from jankovićite to rebulite, the closely related but not identical structures, is explained through necessity to accommodate the smaller volumes of the As coordination polyhedra and is accomplished through unit-cell twinning over the periodic (001)<sub>reb</sub> twin boundaries. The As end-member of the rebulite solid solution is in equilibrium with the phase of Tl<sub>2.4</sub>Sb<sub>0.68</sub>As<sub>7.18</sub>S<sub>13</sub> ideal composition, interpreted as imhofite.


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