Is there an N3− ion in the crystal structure of the ionic conductor lithium nitride (Li3N)?

1978 ◽  
Vol 34 (6) ◽  
pp. 999-1005 ◽  
Author(s):  
H. Schulz ◽  
K. Schwarz
Keyword(s):  
Crystal Structure ◽  
Ionic Crystal ◽  
Ionic Conductor ◽  
Small Range ◽  
Structure Parameters ◽  
Neutral Atoms ◽  
Lithium Nitride ◽  
Temperature Range ◽  
Free Ion

The structure parameters of Li3N in the temperature range -120 to 20°C were refined both for neutral atoms (Li0 and N0) and for ions (Li+ and N3-). For N3- new scattering curves were used which were calculated by applying stabilizing Watson-sphere potentials for different radii. All structure parameters depend critically on the scattering curves used. However, only on the assumption of ions, and only for N3- scattering curves corresponding to a small range of Watson radii, were physically meaningful structure parameters and R values down to 0.9% obtained. These structure refinements demonstrate that Li3N can be considered as an ionic crystal in which the N3- ion, though unstable as a free ion, is stabilized by the surrounding Li+ ions.

NQR and Crystal Structure of 4,5-Dichloroimidazole, C3H2N2Cl2

1992 ◽  
Vol 47 (1-2) ◽  
pp. 177-181 ◽  
Author(s):  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Unit Cell ◽  
Space Group ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Group D

AbstractThe two line 35Cl NQR spectrum of 4,5-dichloroimidazole was measured in the temperature range 77≦ T/K ≦ 389. The temperature dependence of the NQR frequencies conforms with the Bayer model and no phase transition is indicated in the curves v ( 35Cl)= f(T). Also the temperature coefficients of the 35Cl NQR frequencies are "normal". At 77 K the 35Cl NQR frequencies are 37.409 MHz and 36.172 MHz and at 389 K 35.758 MHz and 34.565 MHz. The compound crystallizes at room temperature with the tetragonal space group D44-P41212, Z = 8 molecules per unit cell; at 295 K : a = 684.2(5) pm, c = 2414.0(20) pm. The relations between the crystal structure and the NQR spectrum are discussed.

scholarly journals Synthesis, Crystal Structure and Magnetic Behaviour of Dimeric and Polymeric Gadolinium Trifluoroacetate Complexes

2006 ◽  
Vol 61 (6) ◽  
pp. 699-707 ◽  
Author(s):  
Daniela John ◽  
Alexander Rohde ◽  
Werner Urland
Keyword(s):  
Crystal Structure ◽  
Magnetic Behaviour ◽  
Magnetic Data ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
Temperature Range ◽  
X Ray Crystallography ◽  
Carboxylate Groups

The gadolinium(III) trifluoroacetates ((CH3)2NH2)[Gd(CF3COO)4] (1), ((CH3)3NH)[Gd(CF3 COO)4(H2O)] (2), Gd(CF3COO)3(H2O)3 (3) as well as Gd2(CF3COO)6(H2O)2(phen)3 · C2H5OH (4) (phen = 1,10-phenanthroline) were synthesized and structurally characterized by X-ray crystallography. These compounds crystallize in the space group P1̅ (No. 2, Z = 2) (1, 2 and 4) and P 21/c (No. 14, Z = 4) (3), respectively, with the following lattice constants 1: a = 884.9(2), b = 1024.9(2), c = 1173.1(2) pm, α = 105.77(2), β = 99.51(2), γ = 107.93(2)°; 2: a = 965.1(1), b = 1028.6(1), c = 1271.3(2) pm, α = 111.83(2), β = 111.33(2), γ = 90.44(2)°; 3: a = 919.6(2), b = 1890.6(4), c = 978.7(2) pm, β = 113.94(2)°; 4: a = 1286.7(8), b = 1639.3(8), c = 1712.2(9) pm, α = 62.57(6), β = 84.13(5), γ = 68.28(5)°. The compounds consist of Gd3+ ions which are bridged by carboxylate groups either to chains (1 and 2) or to dimers (3 and 4). In addition to the Gd3+ dimers, compound (4) also contains monomeric Gd3+ units. The magnetic behaviour of 2 and 3 was investigated in a temperature range of 1.77 to 300 K. The magnetic data for these compounds indicate weak antiferromagnetic interactions

scholarly journals Effect of Nd, Pr substitutional atoms on the magnetic and magnetostrictive properties in (Tb-Dy)(Fe-Co)2 Laves phases

2021 ◽  
Vol 2103 (1) ◽  
pp. 012196
Author(s):  
G A Politova ◽  
M A Ganin ◽  
A B Mikhailova ◽  
D A Morozov ◽  
K E Pankov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Laves Phase ◽  
Type Structure ◽  
Partial Substitution ◽  
Laves Phases ◽  
Temperature Range ◽  
Homogenizing Annealing ◽  
Arc Melting ◽  
Magnetostrictive Materials

Abstract Polycrystalline TbxDy1-xR0.1Fe2-zCoz (R = Nd, Pr, x = 0.2, 0.3; z = 0, 1.3) cubic Laves phase alloys with MgCu2-type structure were prepared by arc melting followed by homogenizing annealing. The crystal structure, magnetic properties, and magnetostriction have been investigated. Compounds with high values of magnetostrictive susceptibility were found in the temperature range 150-300 K. Compounds with partial substitution of cobalt for iron demonstrate a change in the sign of anisotropic magnetostriction. This work continues the search for magnetostrictive materials with inexpensive neodymium and praseodymium.

79Br, 127I NQR of Diammoniumalkyl Halides and Piperazinium Halides. Crystal Structure of Piperazinium Dibromide Monohydrate and Piperazinium Monoiodide

1989 ◽  
Vol 44 (1) ◽  
pp. 41-55 ◽  
Author(s):  
Jutta Hartmann ◽  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Temperature Range

Abstract The 79Br and 127I NQR spectra were investigated for 1,2-diammoniumethane dibromide, -diiodide, 1,3-diammoniumpropane dibromide, -diiodide, piperazinium dibromide monohydrate, and piperazinium monoiodide in the temperature range 77 ≦ T/K ≦ 420. Phase transitions could be observed for the three iodides. The temperatures for the phase transitions are: 400 K and 404 K for 1,2-diammoniumethane diiodide, 366 K for 1,3-diammoniumpropane diiodide, and 196 K for piperazinium monoiodide.The crystal structures were determined for the piperazinium compounds. Piperazinium dibromide monohydrate crystallizes monoclinic, space group C2/c, with a= 1148.7 pm, 0 = 590.5 pm, c= 1501.6pm, β = 118.18°, and Z = 4. For piperazinium monoiodide the orthorhombic space group Pmn 21 was found with a = 958.1 pm, b = 776.9 pm, c = 989.3 pm, Z = 4. Hydrogen bonds N - H ... X with X = Br, I were compared with literature data.

Correlation of Zero Field Splittings and Site Distortions V. Mn2+ in Cs2Zn3S4

1983 ◽  
Vol 38 (2) ◽  
pp. 149-153 ◽  
Author(s):  
M. Heming ◽  
G. Lehmann
Keyword(s):  
Fine Structure ◽  
Hyperfine Splitting ◽  
Site Symmetry ◽  
Zero Field ◽  
Structure Parameters ◽  
Zero Field Splitting ◽  
Zero Field Splitting Parameter ◽  
Free Ion ◽  
Splitting Parameter ◽  
Epr Signal

Abstract In platelets of Cs2Zn3S4 with about 4% of the Zn substituted by Mn two nonequivalent centers of isolated Mn2+ were observed in addition to a broad EPR signal near g = 2 which is assigned to clusters of interconnected MnS4 units. The fine structure and hyperfine structure parameters for the single-ion centers (all in units of 1CT 4 cm -1) areb02 = -318.3 ± 3; b22 = -210.3 ± 2; Ay = -62.7; Az = -63.6 ± 0.8;b02 = -890 ± 18; b22 = -743 ± 36; Ay = -60.6; Az = - 61.4 ± 0.8;for centers I and II, resp. Center II arises from Zn sites of C 2 site symmetry while for center I assignment to either one of two sites with D2 site symmetry is possible. The larger hyperfine splitting constants as well as the superposition analysis favor the larger sites which are not occupied by Zn, but are partly occupied in the analogous Mn (and Co) compounds. Superposition analysis yields the same value of + 0.12 ± 0.02 cm-1 for the intrinsic zero field splitting parameter b̄2 of the bridging MnS4 units in both sites. gz is significantly higher than the free ion value indicating a higher degree of covalency than in Cds and CdGa2S4.

Structure of Carbonated Hydroxyapatite Based on Rietveld Method

2008 ◽  
Vol 368-372 ◽  
pp. 1187-1189
Author(s):  
Xu Ran ◽  
Jun Guo Ran ◽  
Li Gou ◽  
Ji Yong Chen ◽  
Jiao Min Luo
Keyword(s):  
Crystal Structure ◽  
Sintering Temperature ◽  
Rietveld Method ◽  
Rietveld Analysis ◽  
Structure Parameters ◽  
X Ray Diffraction ◽  
Carbonated Hydroxyapatite ◽  
X Ray ◽  
Quantitative Results ◽  
Distortion Index

The crystalline structures of B-type carbonated hydroxyapatite (CHA) powders sintered at 700, 900 and 1100°C, respectively, were studied by Rietveld analysis of powder X-ray diffraction (XRD) data. A series of structure parameters, including lattice parameters (a and c), bond length and the distortion index of PO4 tetrahedron (Dind) were calculated by Rietveld method to characterize the fine structure of CHA. The broadening effect of XRD reflections was separated to calculate the micro-strain and crystalline size. The results showed that CHA become more stable with the increase of sintering temperature, but the CO3 2- is almost lost at temperature of 1100°C. The quantitative results about crystal structure of CHA based on crystalline structure simulated by Rietveld method are obtained.

A Study of the Cubic Phase of Solid Acetylene-d2

1975 ◽  
Vol 30 (8) ◽  
pp. 1028-1031
Author(s):  
Harri K. Koski
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Thermal Neutron ◽  
Powder Pattern ◽  
Cubic Phase ◽  
Narrow Temperature Range ◽  
Temperature Range ◽  
Theoretical Pattern ◽  
Neutron Diffraction Technique ◽  
High Phase

Abstract The powder pattern of crystalline cubic deuterated acetylene recorded by thermal neutron diffraction technique and the Pa3 crystal structure assigned to the high phase of C2H2 are com-pared. The observations are not in disagreement with the theoretical pattern. Values for the lattice parameters in a narrow temperature range are given.

scholarly journals The principal magnetic susceptibilities of some paramagnetic crystals at low temperatures

1933 ◽  
Vol 140 (842) ◽  
pp. 695-713 ◽  
Keyword(s):  
Ammonium Sulphate ◽  
Low Temperatures ◽  
Room Temperature ◽  
Manganese Carbonate ◽  
Small Range ◽  
Restricted Range ◽  
Nickel Sulphate ◽  
Temperature Range ◽  
Naturally Occurring ◽  
Ferrous Carbonate

Our knowledge of the temperature variation of the principal susceptibilities of paramagnetic crystals is as yet fragmentary. The principal susceptibilities of a number of paramagnetic crystals have been determined by Finke and by Rabi at room temperature but the first measurements on orientated crystals over any range of temperature were those of Foëx. He has published the principal susceptibilities of siderose (a mineral which is mainly ferrous carbonate but which contains appreciable quantities of the carbonates of manganese and other metals) over the range 87° to 400°K. and some measurements but not actual principal susceptibilities for manganese sulphate, MnSO 4 .4H 2 O. The writer measured the principal susceptibilities of cobalt ammonium sulphate and nickel sulphate, NiSO 4 . 7H 2 O over the temperature range 14°-290°K. and the writer and de Haas have published measurements on manganese ammonium sulphate crystals over the restricted range 14°-20° K. In addition Dupouy has repeated Foëx’s observations on siderose and has measured the principal susceptibilities of dialogite (a naturally occurring manganese carbonate) and oligist (Fe 2 O 3 ), all over a small range of temperature above 0° C. Quite recently Bartlett has employed Rabi’s method to determine the principal susceptibilities of the following compounds, CoSO 4 . 7H 2 O, CoSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O, CoSO 4 . K 2 SO 4 . 6H 2 O, CuSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O CuSO 4 . K 2 SO 4 . 6H 2 O, NiSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O over the temperature range —45° to +55°C. In the writer’s opinion, however, Bartlett’s procedure is liable to several objections.

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