Superconducting and structural properties of rare-earth-based Chevrel-phase selenides REMo6Se8: first single crystal studies

1997 ◽  
Vol 262-263 ◽  
pp. 406-409 ◽  
Author(s):  
F. Le Berre ◽  
O. Peña ◽  
C. Hamard ◽  
R. Horyń ◽  
A. Wojakowski
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Structural Properties ◽  
Chevrel Phase

Magnetic and Structural Properties of Single-Crystal Rare-Earth Gd-Y Superlattices

1985 ◽  
Vol 55 (13) ◽  
pp. 1402-1405 ◽  
Author(s):  
J. Kwo ◽  
E. M. Gyorgy ◽  
D. B. McWhan ◽  
M. Hong ◽  
F. J. DiSalvo ◽  
...  
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Structural Properties

SINGLE CRYSTAL NEUTRON DIFFRACTION STUDIES OF HCP RARE EARTH THORIUM ALLOYS

1971 ◽  
Vol 32 (C1) ◽  
pp. C1-1128-C1-1129
Author(s):  
H. R. CHILD ◽  
W. C. KOEHLER
Keyword(s):  
Rare Earth ◽  
Neutron Diffraction ◽  
Single Crystal

scholarly journals Synthesis, characterization, and single-crystal growth of a high-entropy rare-earth pyrochlore oxide

2020 ◽  
Vol 4 (10) ◽  
Author(s):  
Candice Kinsler-Fedon ◽  
Qiang Zheng ◽  
Qing Huang ◽  
Eun Sang Choi ◽  
Jiaqiang Yan ◽  
...  
Keyword(s):  
Rare Earth ◽  
Crystal Growth ◽  
Single Crystal ◽  
Single Crystal Growth ◽  
High Entropy ◽  
Pyrochlore Oxide

The Ternary Rare Earth Chromium Nitrides Ce2CrN3 and Ln3Cr10−xN11 with Ln = La, Ce, Pr

1995 ◽  
Vol 50 (6) ◽  
pp. 905-912 ◽  
Author(s):  
Sascha Broil ◽  
Wolfgang Jeitschko
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Chromium Nitrides ◽  
First Approximation ◽  
Structure Factors ◽  
Square Planar ◽  
Pauli Paramagnetism ◽  
Cubic Structure ◽  
Cold Pressed ◽  
N Flux

The title compounds have been prepared by annealing cold-pressed pellets of the binary nitrides LnN and CrN. Well developed crystals were obtained by recrystallization of the binary or prereacted ternary nitrides in a Li3N flux. Their structures were determined from single-crystal diffractometer data. C e2CrN3 has a U2CrN3 type structure: Immm , a = 379.0(1), b = 340.4(1), c = 1251.7(2) pm, Z = 2, R = 0.012 for 383 structure factors and 16 variables. The atomic positions of this structure are similar to those of U2IrC2 and K2NiF4. The structure may be rationalized to a first approximation with the formula (Ce+4)2[CrN3]8−. The chromium atoms are in a distorted square-planar nitrogen coordination. The CrN4-squares are linked via corner-sharing nitrogen atoms, thus forming infinite, straight - N - CrN2- N - CrN2- chains. The cubic structure of La3Cr10−xN11 (a = 1298.2(1) pm ), Ce3Cr10−xN11 (with a small homogenity range; a = 1284.3(1)-1286.1(3) pm ), and Pr3Cr10−xN11 (a = 1289.1(2) pm ) was determined for the lanthanum compound: Fm 3̄ m , Z = 8, R = 0.027 for 189 F values and 18 variables. One chromium site was found to have an occupancy of only 80.9(5)% resulting in the composition La3Cr9.24(1)N11. The nitrogen atoms occupy four atomic sites. Three of these have octahedral environments (6 La, 3 La + 3 Cr, 2 La + 4 Cr), the fourth one is surrounded by eight chromium atoms forming a cube. The chromium atoms are tetrahedrally coordinated by nitrogen atoms, and these CrN4-tetrahedra are linked via common corners and edges to form a three-dimensionally infinite polyanionic network. In addition the chromium atoms with oxidation numbers of about 2 to 3 form numerous Cr - Cr bonds, which allow to rationalize the Pauli paramagnetism of the compound.

Critical Current of Bi-2212 Single Crystal by Doping Oxides as a Pinning Center

2014 ◽  
Vol 95 ◽  
pp. 175-180
Author(s):  
Takuya Agou ◽  
Hiroya Imao
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Single Crystals ◽  
Crystal Surface ◽  
Rare Earth Oxides ◽  
Pinning Centers ◽  
Current Path ◽  
Pinning Center ◽  
Superconducting Current ◽  
A Current

It is necessary to formpinning centers in superconductors to allow the flow of large currents throughthe specimens. To clarify the properties of pinning centers, it is preferableto investigate single crystals. In this study, heat treatment was used to dopevarious oxides into Bi2Sr2CaCu2Ox(Bi-2212) single crystals prepared by self-flux methods and the criticalcurrent (Ic) was measured. The oxides used in this study were Al2O3and the rare earth oxides Er2O3and Nd2O3. At 77K, Nd2O3and Er2O3 are magnetic, whereas Al2O3is nonmagnetic. The Ic of the samples were measured as a current per width of 1cm (Ics). The resulting Ics of the Bi-2212 single crystal was 2.8A/cm and thatof the Al2O3 doped Bi-2212 sample was 4.5A/cm. Comparedwith these samples, doping the other rare earth oxides gave Ics values inexcess 10A/cm. The results indicated that the doping oxides were effective inoperating as pinning centers in the samples. We assumed the current path in asingle crystal, and calculated the Ics by superconducting current simulation.The results indicated that the oxides permeated from a crystal surface in aporous shape. The oxides increase the current which flow in the Cu-O2planes that are parallel to the a-b plane.

Structural properties of the guest species in diacyl peroxide/urea inclusion compounds: an X-ray diffraction investigation

1990 ◽  
Vol 431 (1882) ◽  
pp. 245-269 ◽  
Keyword(s):  
Single Crystal ◽  
Structural Properties ◽  
Inclusion Compounds ◽  
X Ray Diffraction ◽  
Channel Axis ◽  
Guest Molecules ◽  
X Ray ◽  
Urea Inclusion Compounds ◽  
Diacyl Peroxide ◽  
Urea Inclusion

In this paper we report single crystal X-ray diffraction studies of urea inclusion compounds containing diacyl peroxides (dioctanoyl peroxide (OP), diundecanoyl peroxide (UP), lauroyl peroxide (LP)) as the guest component. In these inclusion compounds, the host (urea) molecules crystallize in a hexagonal structure that contains linear, parallel, non-intersecting channels (tunnels). The guest (diacyl peroxide) molecules are closely packed inside these channels with a periodic repeat distance that is incommensurate with the period of the host structure along the channel axis. Furthermore, there is pronounced inhomogeneity within the guest structure: within each single crystal, there are regions in which the guest molecules are three-dimensionally ordered, and other regions in which they are only one-dimensionally ordered (along the channel axis). Although it has not proven possible to ‘determine’ the guest structures in the conventional sense, substantial information concerning their average periodicities and their orientational relationships with respect to the host has been deduced from single crystal X-ray diffraction photographs recorded at room temperature. For OP/urea, UP/urea and LP/urea, the guest structure in the three-dimensionally ordered regions is monoclinic, and six types of domain of this monoclinic structure can be identified within each single crystal. The relative packing of diacyl peroxide molecules is the same in each domain, and the different domains are related by 60° rotation about the channel axis. For each of these inclusion compounds, the offset between the ‘heights’ of the guest molecules in adjacent channels is the same ( ca . 4.6 Å (4.6 x 10 -10 m)) within experimental error, suggesting that the relative interchannel packing of the guest molecules is controlled by a property of the diacyl peroxide group. In addition to revealing these novel structural properties, the work discussed in this paper has more general relevance concerning the measurement and interpretation of single crystal X-ray diffraction patterns that are based on more than one three-dimensionally periodic reciprocal lattice. Seven separate reciprocal lattices are required to rationalize the complete X-ray diffraction pattern from each diacyl peroxide/urea crystal studied here.

scholarly journals Rare-Earth Triangular Lattice Spin Liquid: A Single-Crystal Study ofYbMgGaO4

2015 ◽  
Vol 115 (16) ◽  
Author(s):  
Yuesheng Li ◽  
Gang Chen ◽  
Wei Tong ◽  
Li Pi ◽  
Juanjuan Liu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Triangular Lattice ◽  
Spin Liquid ◽  
Lattice Spin ◽  
Single Crystal Study

Single-crystal rare-earth doped YAG fiber lasers grown by the laser-heated pedestal growth technique

2014 ◽  
Author(s):  
Craig D. Nie ◽  
James A. Harrington ◽  
Yuan Li ◽  
Eric G. Johnson ◽  
Elizabeth F. Cloos ◽  
...  
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Fiber Lasers ◽  
Growth Technique ◽  
Laser Heated ◽  
Rare Earth Doped

Structural Systematics of Rare Earth Complexes. VII. Crystal Structure of Bis(2,2'/6',2␛-Terpyridinium) Octaaquaterbium(III) Heptachloride Hydrate

1994 ◽  
Vol 47 (2) ◽  
pp. 391 ◽  
Author(s):  
CJ Kepert ◽  
BW Skeleton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystal ◽  
Structural Characterization ◽  
Title Compound ◽  
Room Temperature ◽  
Chloride Ions ◽  
Full Matrix ◽  
X Ray

The room-temperature single-crystal X-ray structural characterization of the title compound (tpyH2)2[Tb(OH2)8]Cl7.~2⅓H2O is recorded. Crystals are triclinic, Pī , a 17.063(5), b 16.243(3), c 7.878(3) Ǻ, α 84.78(2), β 84.39(3), γ 87.81(2)°, Z = 2 formula units; 3167 'observed' diffractometer reflections were refined by full-matrix least-squares procedures to a residual of 0.057. Notable features of interest of the compound are the 'chelation' of chloride ions by the terpyridinium cations , and the existence of a free [Tb(OH2)8]2+ cation in the presence of an abundance of chloride ions.

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