Hydraulic structures and/or the environment?∗

Rouse, Hunter; Sträub, Conrad P.

doi:10.1080/10643388009381673

Cited by 8 publications

(9 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3). This coordination is very similar to the eightfold square-antiprismatic coordination for Pb found in nadorite, PbSbO2CI (Giuseppetti & Tadini, 1973), PbTiO3 (Shirane, Pepinsky & Frazer, 1956), and diaboleite Pb2Cu(OH)4CI 2 (Rouse, 1971). In bayldonite, all Pb-O bonds are ionic, since all the Pb-O distances (average 2.722 A) are larger than the sum of the ionic radii of Pb 2÷ and 0 2-(2.69 A) (Shannon & Prewitt, 1969).…”

Section: Pbo 8 Polyhedronsupporting

confidence: 75%

Structural chemistry of copper and zinc minerals. VI. Bayldonite, (Cu,Zn)3Pb(AsO4)2(OH)2: a complex layer structure

Ghose¹,

Wan²

1979

Acta Crystallogr Sect B

View full text Add to dashboard Cite

Bayldonite, (Cu,Zn)3Pb(AsOa)2(OH)2 from Tsumeb, S.W. Africa, is monoclinic, space group C2/c, with cell dimensions: a = 10.147(2), b = 5.892(1), c = 14.081 (2) A, fl = 106.05 (1) ° and Z = 4. The crystal structure has been determined by the heavy-atom method and refined by the full-matrix least-squares method to an R factor of 0.053 for 1057 observed Xray reflections. The crystal structure of bayldonite consists of interconnected Cu octahedral layers and lead arsenate polyhedral-tetrahedral layers which alternate along the c axis, giving rise to complex pseudohexagonal layers parallel to (001). The Cu octahedral sheet, with six-membered octahedral tings, is formed by three crystallographically indep_endent [CuO4(On)2] octahedra with point symmetry 1, showing Jahn-Teller distortion; the square-planar Cu-O (or OH) distances vary from 1.878 to 2.087 A (average 1.970 A), whereas the apical Cu-O distances vary from 2.272 to 2.474 A. The PbO s polyhedron is a square antiprism with an average Pb--O bond length of 2.722/k. The tetrahedral As-O bond lengths vary from 1.66 to 1.724 A (average 1-696 A). The H atom appears to be disordered between the (OH) group and a highly charge-deficient O atom, which is bonded to one Pb atom, in addition to the As atom. The observed twinning, cleavage and crystal habit result from the pseudohexagonal nature of the layer structure.

show abstract

Section: Pbo 8 Polyhedronsupporting

confidence: 75%

Structural chemistry of copper and zinc minerals. VI. Bayldonite, (Cu,Zn)3Pb(AsO4)2(OH)2: a complex layer structure

Ghose¹,

Wan²

1979

Acta Crystallogr Sect B

View full text Add to dashboard Cite

show abstract

“…Surprisingly, an appropriate structural analog of PbVO 3 can be found in a completely different family of materials. The Cu-based mineral diaboleite, Pb 2 Cu(OH) 4 Cl 2 , has tetragonal crystal structure 23,24 that can be derived from the perovskite structure type.…”

Section: Introductionmentioning

confidence: 99%

Square-lattice magnetism of diaboleite Pb2Cu(OH)4Cl2

et al. 2013

View full text Add to dashboard Cite

We report on the quasi-two-dimensional magnetism of the natural mineral diaboleite Pb2Cu(OH)4Cl2 with a tetragonal crystal structure, which is closely related to that of the frustrated spin-1/2 magnet PbVO3. Magnetic susceptibility of diaboleite is well described by a Heisenberg spin model on a diluted square lattice with the nearest-neighbor exchange of J~35 K and about 5% of non-magnetic impurities. The dilution of the spin lattice reflects the formation of Cu vacancies that are tolerated by the crystal structure of diaboleite. The weak coupling between the magnetic planes triggers the long-range antiferromagnetic order below TN~11 K. No evidence of magnetic frustration is found. We also analyze the signatures of the long-range order in heat-capacity data, and discuss the capability of identifying magnetic transitions with heat-capacity measurements.Comment: 10 pages, 10 figures + Supplementary Informatio

show abstract

“…The average resulting displacement of Nb from the center of its O-atom octahedron at 543 K is 0.167 (9)A, corresponding to a Curie temperature predicted from (1) of 560 (60)K, in satisfactory agreement with experiment. mined by Rouse (1971) on the basis of 173 independent reflections obtained by averaging a hemisphere of data including Bijvoet pairs. The starting model used the results of an earlier study [ARKEA 2 397] and led to R = 0.05; no improvement was obtained on changing from isotropic to anisotropic atomic displacement parameters.…”

Section: Knbomentioning

confidence: 99%

New ferroelectric inorganic materials predicted in point group 4mm

Abrahams¹

1996

Acta Crystallogr Sect B

View full text Add to dashboard Cite

The Inorganic Crystal Structure Database containg a total of 209 entries for 128 different materials reported in point group 4mm, of which eight are for previously known ferroelectrics. Analysis of the remaining entries, assuming the structure determinations reported are correct, leads to the prediction of an additional 43 new ferroelectric materials. 15 were determined in space group P4mm, 11 in P4bm, one in P42nm, one in P4cc, two in P42mc, one in P42bc, seven in 14mm, two in 14cm, one in 141md and two in 14led.

show abstract

Hydraulic structures and/or the environment?∗

Cited by 8 publications

References 2 publications

Structural chemistry of copper and zinc minerals. VI. Bayldonite, (Cu,Zn)3Pb(AsO4)2(OH)2: a complex layer structure

Structural chemistry of copper and zinc minerals. VI. Bayldonite, (Cu,Zn)3Pb(AsO4)2(OH)2: a complex layer structure

Square-lattice magnetism of diaboleite Pb2Cu(OH)4Cl2

New ferroelectric inorganic materials predicted in point group 4mm

Contact Info

Product

Resources

About