New family of silicate phases with the pollucite structure

Torres-Martı́nez, Leticia M.; West, Anthony R.

doi:10.1524/zkri.1986.175.1-2.1

Cited by 17 publications

(3 citation statements)

References 7 publications

(6 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where T1 + occupies the W-site. Thus it is natural that in the A1/Si disordering the synthetic Tl-leucite should accord with natural -Martinez and West, 1986); KFeSi206 (Bell and Henderson, 1994); RbA1Si206 (Martin and Lagache, 1987); RbGaSi206 (Torres-Martinez and West, 1986); RbFeSi206 (Bell and Henderson, 1994); CsA1Si206 (Newnham, 1967); CsFeSi206 (Bell and Henderson, 1994). Mazzi et al (1976).…”

Section: Site-preference Of Ti Cationmentioning

confidence: 99%

Synthesis of thallium-leucite (TlAlSi₂O₆) pseudomorph after analcime

Kyono

Kimata²,

Shimizu³

et al. 1999

Mineral. mag.

View full text Add to dashboard Cite

Thallium leucite, TlAlSi 2 O 6 , has been synthesized at 4508C for 7 days, under ambient conditions, by the transformation of dehydrated analcime NaAlSi 2 O 6 in the presence of excess TlCl. This substitution of Tl for Na leads to confirmation of a thallium-leucite pseudomorph after analcime. Their optical properties, X-ray powder diffraction patterns, electron microprobe analysis, infrared spectra, and X-ray photoelectron spectroscopy have characterized the synthetic Tl-leucites. The IR spectra show that the mid-IR modes T-O stretching and T-O-T bending vibrations for TlAlSi 2 O 6 are more resemblant of those for analcime than for leucite, KAlSi 2 O 6 . This resemblance implies that Tl cation enters the W-site rather than the S-site in the analcime structure: Na (S)where & represents an S-site vacancy. The mechanism of this substitution is supported by the crystal chemical constraints: inasmuch as the S-site is smaller than the W-site, Tl + cations being larger than Na + plainly prefer the latter site to the former. One inference from the binding energy for Tl + by XPS is that Tl + occupies the extra-framework site in synthetic leucite pseudomorph, rather than the smaller tetrahedral site. The difference in Al/Si disordering between analcime and leucite and the nonstoichiometry due to the solid solution of the &Si 3 O 6 component into the leucite structure may provide a fundamental insight into understanding why TlAlSi 2 O 6 deviates from the trend defined by K-, Rb-and CsAlSi 2 O 6 leucite series on the a-c parameter diagram, inasmuch as these three cations in the leucite structure occupy the W-sites. Finally, synthesis of TlAlSi 2 O 6 leucite has an implication for the existence of other polymorphs due to different degrees of Al/Si disordering, except for high-and low-temperature leucites already known: natural leucites crystallized directly through igneous processes are different from those formed by substitution of K for Na in analcimes.

show abstract

Section: Site-preference Of Ti Cationmentioning

confidence: 99%

Synthesis of thallium-leucite (TlAlSi₂O₆) pseudomorph after analcime

Kyono

Kimata²,

Shimizu³

et al. 1999

Mineral. mag.

View full text Add to dashboard Cite

show abstract

“…Tetragonal and cubic leucite structures may also occur if some T-site atoms are replaced by trivalent transition elements or divalent cations. These analogues have the stoichiometries ACSi 2 O 6 and A 2 BSi 5 O 12 , where A is an alkali metal cation (K, Rb, Cs), B is a divalent metal cation (Be, Mg, Fe 2+ ,Co,Ni,Zn,Cd), and C is a trivalent metal cation (Al, Fe 3+ ; Torres-Martinez & West, 1986, 1989Bell & Henderson, 1994a,b;Henderson et al, 1998). All of these structures have disordered framework cations on the tetrahedrally coordinated (T) sites.…”

Section: Introductionmentioning

confidence: 99%

Revision of the structure of Cs₂CuSi₅O₁₂ leucite as orthorhombic Pbca

Bell

Knight

Henderson

et al. 2010

Acta Crystallogr Sect B

View full text Add to dashboard Cite

The crystal structure of a hydrothermally synthesized leucite analogue Cs(2)CuSi(5)O(12) has been determined and refined using the Rietveld method from high-resolution synchrotron X-ray and neutron powder diffraction data. This structure is based on the topology and cation-ordering scheme of the Pbca leucite structure of Cs(2)CdSi(5)O(12), and exhibits five ordered Si sites and one ordered Cu tetrahedrally coordinated (T) site. This structure for Cs(2)CuSi(5)O(12) is topologically identical to other known leucite structures and is different from that originally proposed by Heinrich & Baerlocher [(1991), Acta Cryst. C47, 237-241] in the tetragonal space group P4(1)2(1)2. The crystal structure of a dry-synthesized leucite analogue Cs(2)CuSi(5)O(12) has also been refined; this has the Ia3d cubic pollucite structure with disordered T sites.

show abstract

“…Analogues of these tetragonal and cubic leucite structures can also be prepared synthetically if the alkali metal cation and/or the non-silicon tetrahedral cations are replaced by other alkali metal cations and divalent or trivalent cations. This results in silicate framework structures with stoichiometries of ACSi 2 O 6 and A 2 BSi 5 O 12 , where A is an alkali metal cation (also ammonium, see Hori et al, 1986), B is a divalent metal cation and C is a trivalent metal cation (Torres-Martinez & West, 1986, 1989Bell & Henderson, 1994a,b;Palmer et al, 1997). The compositional flexibility of this structure type is reviewed in Henderson et al (1998).…”

Section: Introductionmentioning

confidence: 99%

Crystal structures and cation ordering in Cs₂MgSi₅O₁₂, Rb₂MgSi₅O₁₂ and Cs₂ZnSi₅O₁₂ leucites

Bell

Henderson

2009

Acta Crystallogr Sect B

View full text Add to dashboard Cite

The crystal structures of the leucite analogues Cs(2)MgSi(5)O(12), Cs(2)ZnSi(5)O(12) and Rb(2)MgSi(5)O(12) have been determined by synchrotron X-ray powder diffraction using Rietveld refinement in conjunction with (29)Si MAS NMR spectroscopy. These leucites are framework structures with distinct tetrahedral sites (T sites) occupied by Si and a divalent cation (either Mg or Zn in these samples); there is also a monovalent extra-framework cation (either Cs or Rb in these samples). The refined crystal structures were based on the Pbca leucite structure of Cs(2)CdSi(5)O(12), thus a framework with five ordered Si T sites and one ordered Cd T site was used as the starting model for refinement. (29)Si MAS NMR shows five distinct Si T sites for Cs(2)MgSi(5)O(12) and Rb(2)MgSi(5)O(12), but six Si T sites for Cs(2)ZnSi(5)O(12). The refined structures for Cs(2)MgSi(5)O(12) and Rb(2)MgSi(5)O(12) were determined with complete T-site ordering, but the refined structure for Cs(2)ZnSi(5)O(12) was determined with partial disorder of Mg and Si over two of the T sites.

show abstract

New family of silicate phases with the pollucite structure

Cited by 17 publications

References 7 publications

Synthesis of thallium-leucite (TlAlSi₂O₆) pseudomorph after analcime

Synthesis of thallium-leucite (TlAlSi₂O₆) pseudomorph after analcime

Revision of the structure of Cs₂CuSi₅O₁₂ leucite as orthorhombic Pbca

Crystal structures and cation ordering in Cs₂MgSi₅O₁₂, Rb₂MgSi₅O₁₂ and Cs₂ZnSi₅O₁₂ leucites

Contact Info

Product

Resources

About

New family of silicate phases with the pollucite structure

Cited by 17 publications

References 7 publications

Synthesis of thallium-leucite (TlAlSi2O6) pseudomorph after analcime

Synthesis of thallium-leucite (TlAlSi2O6) pseudomorph after analcime

Revision of the structure of Cs2CuSi5O12 leucite as orthorhombic Pbca

Crystal structures and cation ordering in Cs2MgSi5O12, Rb2MgSi5O12 and Cs2ZnSi5O12 leucites

Contact Info

Product

Resources

About

Synthesis of thallium-leucite (TlAlSi₂O₆) pseudomorph after analcime

Synthesis of thallium-leucite (TlAlSi₂O₆) pseudomorph after analcime

Revision of the structure of Cs₂CuSi₅O₁₂ leucite as orthorhombic Pbca

Crystal structures and cation ordering in Cs₂MgSi₅O₁₂, Rb₂MgSi₅O₁₂ and Cs₂ZnSi₅O₁₂ leucites