Ln3Cu4P4O2: a New Lanthanide Transition Metal Pnictide Oxide Structure Type

1996 ◽  
Vol 453 ◽  
Author(s):  
R. J. Cava ◽  
H. W. Zandbergen ◽  
J. J. Krajewski ◽  
T. Siegrist ◽  
H. Y. Hwang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Transition Metal ◽  
Homologous Series ◽  
Structure Type ◽  
Magnetic Susceptibilities ◽  
Oxide Structure ◽  
Trivalent Lanthanides ◽  
New Type

AbstractA new type of lanthanide transition metal pnictide-oxide, Ln3Cu4P4O2 (for Ln = La, Ce, and Nd), is reported. The crystal structure is made from Ln2O2 layers of the Pb2O2 type stacked with layers of Cu2P2 tetrahedra. The existence of a homologous series of compounds with similar chemistry connecting the BiCuOSe and ThCr2Si2 structure types is indicated. The resistivity of La3Cu4P4O2 is metallic, with no superconductivity observed above 2K. The Ce and Nd compounds have magnetic susceptibilities characteristic of the trivalent Lanthanides. The Ce compound orders magnetically at approximately 0.8 K.

Crystal chemistry of transition metal diarsenates M 2As2O7 (M = Mn, Co, Ni, Zn): variants of the thortveitite structure

2010 ◽  
Vol 66 (6) ◽  
pp. 603-614 ◽  
Author(s):  
Matthias Weil ◽  
Berthold Stöger
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Transition Metal ◽  
Basic Structure ◽  
Structure Type ◽  
Ambient Conditions ◽  
Modulated Structure ◽  
Triclinic Crystal System ◽  
Space Groups ◽  
Unit Cells

The structures of the 3d divalent transition-metal diarsenates M 2As2O7 (M = Mn, Co, Ni, Zn) can be considered as variants of the monoclinic (C2/m) thortveitite [Sc2Si2O7] structure type with a ≃ 6.7, b ≃ 8.5, c ≃ 4.7 Å, α ≃ 90, β ≃ 102, γ ≃ 90° and Z = 2. Co2As2O7 and Ni2As2O7 are dimorphic. Their high-temperature (β) polymorphs adopt the thortveitite aristotype structure in C2/m, whereas their low-temperature (α) polymorphs are hettotypes and crystallize with larger unit cells in the triclinic crystal system in space groups P\bar 1 and P1, respectively. Mn2As2O7 undergoes no phase transition and likewise adopts the thortveitite structure type in C2/m. Zn2As2O7 has an incommensurately modulated crystal structure [C2/m(α,0,γ)0s] with q = [0.3190 (1), 0, 0.3717 (1)] at ambient conditions and transforms reversibly to a commensurately modulated structure with Z = 12 (I2/c) below 273 K. The Zn phase resembles the structures and phase transitions of Cr2P2O7. Besides descriptions of the low-temperature Co2As2O7, Ni2As2O7 and Zn2As2O7 structures as five-, three- and sixfold superstructures of the thortveitite-type basic structure, the superspace approach can also be applied to descriptions of all the commensurate structures. In addition to the ternary M 2As2O7 phases, the quaternary phase (Ni,Co)2As2O7 was prepared and structurally characterized. In contrast to the previously published crystal structure of the mineral petewilliamsite, which has the same idealized formula and has been described as a 15-fold superstructure of the thortveitite-type basic structure in space group C2, synthetic (Ni,Co)2As2O7 can be considered as a solid solution adopting the α-Ni2As2O7 structure type. Differences of the two structure models for (Ni,Co)2As2O7 are discussed.

A new type of oxide structure: the crystal structure of rhenium(VII) oxide

1968 ◽  
Vol 0 (5) ◽  
pp. 263-264 ◽  
Author(s):  
B. Krebs ◽  
A. Müller ◽  
H. Beyer
Keyword(s):  
Crystal Structure ◽  
Oxide Structure ◽  
New Type

Nd7,33Ta8O28CI6 — ein Zwischenprodukt des thermischen Abbaus von Nd2Ta2O7Cl2: Präparation, Struktur und magnetische Eigenschaften / Nd7,33Ta8O28Cl6 — an Intermediate Product of the Thermal Decomposition of Nd2Ta2O7Cl2: Preparation, Crystal Structure and Magnetic Properties

1988 ◽  
Vol 43 (12) ◽  
pp. 1567-1574 ◽  
Author(s):  
U. Schaffrath ◽  
R. Gruehn
Keyword(s):  
Crystal Structure ◽  
Thermal Decomposition ◽  
Magnetic Properties ◽  
Calculated Data ◽  
Chemical Transport ◽  
Structure Type ◽  
Magnetic Susceptibilities ◽  
Relationship Of ◽  
The Relationship ◽  
Preparative Route

Abstract Single crystals of the new oxochlorotantalate Nd7.33Ta8O28Cl6, could be obtained only by chemical transport reactions (T2 → T1; T2 - 1000 °C, T, = 900 °C) with mixtures of Cl2/TaCl5 as transport agent. NdTaO4 was chosen as the starting material. A direct preparative route to Nd7.33Ta8O28Cl6 from binary and ternary components, however, was not successful. Nd7.33Ta8O28Cl6 , crystallizes in the space group Cmmm with a = 10.3381(8) Å, b = 18.865(1) Å, c - 3.9152(3) A; Z = 1. The structure was refined to R - 4.42%, R w = 2.76%. Main building units are pairs of edge-sharing TaO6 -octahedra which are connected with threefold capped trigonal prisms around Nd. Especially remarkable is one Nd position with an occupation factor of 0.833. The relationship of this new structure type with Nd2Ta2O7Cl2 is considered. Furthermore, we have measured the magnetic susceptibilities of both Nd-compounds in a temperature range from 3,6 to 251,3 K. The results are compared with calculated data.

The crystal chemistry of (Mn3 +, Fe3+)-substituted andalusites (viridines and kanonaite), (Al1−x−yMn3x+Fe3y+)2 (OǀSiO4): crystal structure refinements, Mössbauer, and polarized optical absorption spectra

1981 ◽  
Vol 155 (1-2) ◽  
Author(s):  
I. Abs-Wurmbach ◽  
K. Langer ◽  
F. Seifert ◽  
E. Tillmanns
Keyword(s):  
Crystal Structure ◽  
Transition Metal ◽  
Optical Absorption ◽  
Metal Ions ◽  
Crystal Chemistry ◽  
Mixed Crystal ◽  
Transition Metal Ions ◽  
Structure Type ◽  
Optical Absorption Spectra ◽  
Distorted Octahedral

AbstractThe crystal chemistry of viridines and kanonaite, (AlThe structure refinements reveal that the transition metal ions substitute for Al almost exclusively in the distorted octahedral Al(l) site of the andalusite structure type within the entire mixed crystal series. This is independently proven by the Mössbauer results for

scholarly journals Inorganic Co-Crystal Formation and Thermal Disproportionation in a Dicyanometallate 'Superperovskite'

2019 ◽  
Author(s):  
Joshua A. Hill ◽  
Claire A. Murray ◽  
Chiu C. Tang ◽  
Peter M. M. Thygesen ◽  
Amber L. Thompson ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transformation ◽  
Perovskite Structure ◽  
Structure Type ◽  
Crystal Formation ◽  
Thermally Driven ◽  
New Type ◽  
A Site ◽  
Inorganic Components

<div> <div> <div> <p>We report the synthesis, crystal structure, and thermally- driven phase transformation of the dicyanometallate super- perovskite co-crystal [NBu4]Mn[Au(CN)2]3·[NBu4]ClO4. This phase is understandable in terms of the conventional ABX3 perovskite structure type, but with the NBu+4 A-site cation displaced onto the perovskite cage face and 1-dimensional AX′ chains included within framework pores opened up by these displacements. On heating to 380K, the co-crystal disproportionates into its two inorganic components: a bcs-structured ABX3 phase and [NBu4 ]ClO4 . This system illustrates a new type of structural and phase complexity accessible to dicyanometallate perovskites. </p> </div> </div> </div>

Synthese und Kristallstruktur von Pt2Sn2Zn3, der ersten ternären Verbindung im System Pt/Sn/Zn / Synthesis and Crystal Structure of Pt2Sn2Zn3, the First Ternary Compound of the Pt/Sn/Zn System

2006 ◽  
Vol 61 (7) ◽  
pp. 862-866 ◽  
Author(s):  
Rainer Lux ◽  
Harald Hillebrecht
Keyword(s):  
Crystal Structure ◽  
Transition Metal ◽  
Single Crystals ◽  
Ternary Compound ◽  
Structure Type ◽  
Synthesis And Crystal Structure ◽  
Binary Compounds

Single crystals of Pt2Sn2Zn3, the first ternary compound in the system Pt/Sn/Zn, have been synthesised from the elements. Pt2Sn2Zn3 exhibits a new structure type (hP14, P63/mmc, Z = 2, a = 4.3367(5), c = 15.532(3) Å , 402 reflections, 14 variables, R1(F) = 0.025, wR2(I) = 0.059) with motifs of the binary compounds. One Pt atom has a cubic environment (PtSn6Zn2), the second one forms an Edshammer polyhedron (PtSn2Zn9). Pt2Sn2Zn3 is one of the few examples of a ternary Sn/Zn compound of a transition metal.

A new tilt and an old twist on the nickel arsenide structure-type: synthesis and characterisation of the quaternary transition-metal cyanamides A2MnSn2(NCN)6 (A = Li and Na)

2019 ◽  
Vol 48 (40) ◽  
pp. 15029-15035 ◽  
Author(s):  
Alex J. Corkett ◽  
Richard Dronskowski
Keyword(s):  
Crystal Structure ◽  
Transition Metal ◽  
Structure Type ◽  
Type Synthesis

Two quaternary transition-metal cyanamides with a novel crystal structure are stabilised through cyanamide tilts and octahedral twists.

Ln3Cu4P4O2: A New Lanthanide Transition Metal Pnictide Oxide Structure Type

1997 ◽  
Vol 129 (2) ◽  
pp. 250-256 ◽  
Author(s):  
R.J Cava ◽  
H.W Zandbergen ◽  
J.J Krajewski ◽  
T Siegrist ◽  
H.Y Hwang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Structure Type ◽  
Oxide Structure
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