Crystal Structures of Tetragonal NdPc2O and NdPc2Clx,O1-x Obtained from NdPc2H by Anodic Crystal Growth

Single crystals of α-HgCrO4, β -HgCrO4 and HgCrO4 ・ H2O were obtained by reacting yellow HgO in chromic acid of various concentrations under hydrothermal conditions at 200 °C (4 d). All crystal structures were solved and refined from single crystal diffractometer data sets [α-HgCrO4: P21/n, Z = 4, a = 5.5079(8), b = 8.5266(12), c = 7.3503(10) Å , β = 94.022(3)°, 955 structure factors, R[F2 > 2σ (F2)] = 0.0296; β -HgCrO4: Cmcm, Z = 4, a = 5.7187(9), b = 9.0169(14), c = 7.0114(11) Å, 361 structure factors, R[F2 > 2σ (F2)] = 0.0275; HgCrO4 ・ H2O: P1̅, Z = 2, a=5.6157(15), b =6.1115(16), c= 7.590(2) Å , α =108.850(5), β =91.666(5), γ =116.569(5)°, 1235 structure factors, R[F2 > 2σ (F2)] = 0.0316]. The previously reported structure of α-HgCrO4 has been re-determined. It contains distorted [HgO7] pentagonal bipyramids in which the short bonds are directed towards the apices. The new polymorph β -HgCrO4 adopts the CrVO4 (β -CrPO4) structure type and is composed of slightly distorted [HgO6] octahedra. The previously unknown monohydrate HgCrO4 ・ H2O crystallizes in an unique structure and is composed of one nearly regular [HgO4(H2O)2] octahedron and one considerably distorted [HgO6] octahedron. All three structures contain tetrahedral chromate anions CrO42− as the second building units with average Cr-O distances of ca. 1.65 Å

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High pressure mixed alkali disilicates in the system Na2— xKxSi2O5: hydrothermal synthesis and crystal structures of NaKSi2O5-II and Na0.67K1.33Si2O5

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.218.6.413.20720 ◽

2003 ◽

Vol 218 (6) ◽

Cited By ~ 4

Author(s):

S. Rakić ◽

V. Kahlenberg ◽

B. C. Schmidt

Keyword(s):

High Pressure ◽

Crystal Growth ◽

Hydrothermal Synthesis ◽

Single Crystal ◽

Crystal Structures ◽

Single Crystal Growth ◽

Mixed Alkali ◽

Growth Experiments

AbstractSingle crystal growth experiments for NaKSi

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Single-Crystal Synthesis

Physics of Spin-Orbit-Coupled Oxides ◽

10.1093/oso/9780199602025.003.0006 ◽

2021 ◽

pp. 161-178

Author(s):

Gang Cao ◽

Lance E. DeLong

Keyword(s):

Crystal Growth ◽

Transition Metal ◽

Metal Oxides ◽

Single Crystals ◽

Crystal Structures ◽

Transition Metal Oxides ◽

Magnetic Moments ◽

Spin Orbit ◽

Spin Orbit Interactions ◽

Almost All

Growing single crystals of 4d- and 5d-transition metal oxides is often difficult, as they tend to form incongruently, as well as having high vapor pressure and high melting points. Two crystal growth techniques are commonly used for transition metal oxides—flux and floating-zone techniques; each has advantages and disadvantages. An established capability in both techniques makes it possible to grow single crystals of almost all stable materials. Some basic aspects of both techniques are discussed, and a few general remarks on crystal growth of 4d- and 5d-transition metal oxides are presented. Crystal structures of most 4d- and 5d-transition metal oxides are inherently distorted. An innovative “field-altering” technique is under development, in which an applied magnetic field aligns magnetic moments and, through strong spin-orbit interactions and magnetoelastic coupling, alters crystal structures at high temperatures. Preliminary results show that a field-altering technology is highly effective for resolving physical properties of spin-orbit-coupled oxides.

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