Neutron Powder Diffraction Study of the Structures of La1.9Ca1.1Cu2O6 and La1.9Sr1.1Cu2O6+δ

ABSTRACTThe title compounds are structurally isomorphous and crystallize with the symmetry of space group 14/mmm. The lattice parameters are a = 3.8248(1), c = 19.4286(5)Å for La1.9Ca1.1Cu2O6 and a = 3.8601(1), c = 19.9994(5)Å for La1.9Sr1.1Cu2O6+δ. The structure can be easily derived from that of La2CuO4 by substituting the layers of composition CuO2 present in La2CuO4 with a block of three layers having composition and sequence (CuO2) - (R) - (CuO2), where R is Ca, Sr, and/or La. Although the general structural configuration is the same for the Ca and the Sr compounds, the distribution of the metal atoms is different in the two cases. More specifically, in La1.9Ca1.1Cu2O6 the perovskite-type layers form blocks with sequence (CuO2) - (Ca) - (CuO2), and are separated by rock-salt blocks of two layers (LaO) - (LaO). In La1.9Sr1.1Cu2O6+δ, on the other hand, the perovskite-type blocks have composition and sequence (CuO2) - (R) - (CuO2) and they are separated by blocks (NO) - (NO), where both R and N are about 65%La and 35%Sr.

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Crystallographic data about hydrated and anhydrous lithium monoborates

Powder Diffraction ◽

10.1017/s0885715600009635 ◽

1997 ◽

Vol 12 (3) ◽

pp. 155-159 ◽

Cited By ~ 7

Author(s):

E. Bétourné ◽

M. Touboul

Keyword(s):

Diffraction Study ◽

Water Content ◽

Powder Diffraction ◽

Structural Formula ◽

Crystallographic Data ◽

The Other ◽

Crystal Data ◽

Space Group ◽

X Ray ◽

Cell Parameters

The anhydrous and hydrated lithium monoborates have been studied. The most hydrated phase is LiBO2·8H2O; its structural formula in the P3 space group is Li(H2O)4B(OH)4·2H2O. Refinement of the cell parameters yielded the following results: a=6.5483(5) Å, c=6.1692(7) Å with F(30)=64(0.015, 32), Z=1, and Dx=1.402 g/cm3. This phase gives LiB(OH)4 by spontaneous dehydration. An X-ray powder diffraction study of LiB(OH)4 as a function of temperature indicated three poorly crystallized hydrates. Two of these hydrates have the formula LiBO2·0.3H2O; the other, LiBO2·xH2O, has an undetermined water content. Crystal data for α-LiBO2 have been obtained: a=5.8473(10) Å, b=4.3513(6) Å, c=6.4557(10) Å, β=115.08(1)°, F(27)=58.5(0.001, 41); space group P21/c, Z=4, and Dx=2.18 g/cm3. β-LiBO2 does not exist but corresponds to the α-LiBO2 form observed at 600 °C. Numerous other LiBO2 forms reported recently have not been found.

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Confirmation of the monoclinic Cc space group for the ground state phase of Pb(Zr0.525Ti0.475)O3: A combined synchrotron X-ray and neutron powder diffraction study

Applied Physics Letters ◽

10.1063/1.4790569 ◽

2013 ◽

Vol 102 (5) ◽

pp. 052903 ◽

Cited By ~ 13

Author(s):

Ravindra Singh Solanki ◽

Sunil Kumar Mishra ◽

Anatoliy Senyshyn ◽

Songhak Yoon ◽

Sunggi Baik ◽

...

Keyword(s):

Diffraction Study ◽

Powder Diffraction ◽

Ground State ◽

Neutron Powder Diffraction ◽

Space Group ◽

X Ray

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Neutron powder diffraction study on Li1.8Na0.2MgCl4

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.220.2.211.59130 ◽

2005 ◽

Vol 220 (2/3) ◽

Author(s):

René Nagel ◽

Heinz Dieter Lutz

Keyword(s):

Crystal Structure ◽

Diffraction Study ◽

Powder Diffraction ◽

Neutron Powder Diffraction ◽

Inverse Spinel ◽

Spinel Type ◽

Space Group ◽

Type Space

AbstractThe crystal structure of inverse spinel-type (space group

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Neutron Diffraction Study of the Hexagonal Perovskite-Type Compound LaCrGe3

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.194.71 ◽

2012 ◽

Vol 194 ◽

pp. 71-74 ◽

Cited By ~ 8

Author(s):

J.M. Cadogan ◽

Pierric Lemoine ◽

Brianna R. Slater ◽

Arthur Mar ◽

Maxim Avdeev

Keyword(s):

Neutron Diffraction ◽

Diffraction Study ◽

Magnetic Structure ◽

Powder Diffraction ◽

Magnetic Moment ◽

Neutron Diffraction Study ◽

Neutron Powder Diffraction ◽

Type Structure ◽

Ferromagnetic Structure ◽

Perovskite Type

The BaNiO3-type structure and the ferromagnetic order (TC = 78 K) of the Cr sublattice in LaCrGe3 have been confirmed by neutron powder diffraction measurements. At 20 K, the magnetic structure is collinear along the c axis with a Cr magnetic moment of 1.24(4) μB. Below 3 K, LaCrGe3 has a spin-canted ferromagnetic structure with a canting angle θ of 32(6) and a Cr magnetic moment of 1.31(4) μB at 1.7 K.

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