Colossal Magnetoresistance in Ti Lightly Doped Cr2Se3 Single Crystals with a Layered Structure

Triclinic single crystals of Cu2(H2O)4[C4H4N2][C6H2(COO)4]·2H2O have been grown in anaqueous silica gel. Space group P-1 (Nr. 2), a = 723.94(7) pm, b = 813.38(14) pm, c = 931.0(2) pm, α = 74.24(2)°, β = 79.24(2)°, γ = 65.451(10)°, V = 0.47819(14) nm3, Z = 1. Cu2+ is coordinated in a distorted, octahedral manner by two water molecules, three oxygen atoms ofthe pyromellitate anions and one nitrogen atom of pyrazine (Cu—O 194.1(2)–229.3(3) pm;Cu–N 202.0(2) pm). The connection of Cu2+ and [C6H2(COO)4)]4− yields infinite strands,which are linked by pyrazine molecules to form a two-dimensional coordination polymer.Thermogravimetric analysis in air showed that the dehydrated compound was stable between175 and 248 °C. Further heating yielded CuO.

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Super Deformable Behavior in Layered Structure InSe Single Crystals

Chinese Physics B ◽

10.1088/1674-1056/ab99bc ◽

2020 ◽

Author(s):

Bin Zhang ◽

Hong Wu ◽

Kunling Peng ◽

Xingchen Shen ◽

Xiangnan Gong ◽

...

Keyword(s):

Single Crystals ◽

Layered Structure

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Effect of Sintering Parameter on the Microstructure and Electrical Properties for Bi2Se3 Topological Insulator Crystals

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.709.172 ◽

2013 ◽

Vol 709 ◽

pp. 172-175

Author(s):

Li Lv ◽

Min Zhang ◽

Li Qin Yang ◽

Xin Sheng Yang ◽

Yong Zhao

Keyword(s):

Electrical Properties ◽

Cooling Rate ◽

Single Crystals ◽

Carrier Concentration ◽

Topological Insulator ◽

Layered Structure ◽

Phase Structure ◽

Lattice Parameter ◽

Holding Time ◽

Type Conductivity

Single crystals of Bi2Se3 topological insulators have been prepared though melt-grown reaction. The sintering parameters of holding time and cooling rate obviously affect the phase structure and electrical properties. The samples with layered structure can be perpendicular cleaved with (0 0 L) axis. All the samples show n-type conductivity caused by the existence of Se vacancies. For low cooling rate, more Se atoms anti-occupy Bi lattice sites, which decreases c-axis lattice parameter and increases carrier concentration n; high cooling rate increases c and decreases n because of less Se atoms occupying Bi lattice sites. Increasing holding time firstly decreases the ratio of Se atoms occupying Bi lattice sites and then increases it, which gives rise to c firstly increase then decrease and n firstly decrease then increase.

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Notizen: The Crystal Structure of MnIn2Se4, a Ternary Layered Semiconductor

Zeitschrift für Naturforschung B ◽

10.1515/znb-1991-0825 ◽

1991 ◽

Vol 46 (8) ◽

pp. 1122-1124 ◽

Cited By ~ 18

Author(s):

K.-J. Range ◽

U. Klement ◽

G. Döll ◽

E. Bucher ◽

J. R. Baumann

Keyword(s):

Crystal Structure ◽

Single Crystals ◽

Layered Structure ◽

Chemical Vapour ◽

Vapour Phase ◽

Tetrahedral Coordination ◽

Layered Semiconductor ◽

Vapour Phase Transport ◽

Phase Transport ◽

Transport Technique

Single crystals of MnIn2Se4 have been grown by the chemical vapour phase transport technique using AlCl3 as the transporting agent. The structure was refined to R = 0.064, Rw, = 0.059 for 609 reflections. MnIn2Se4 (R 3̄m, hexagonal axes a = 4.051(1), c = 39.464(2) Å, c/a = 9.74, Z = 3) crystallizes with a nearly close-packed layered structure (sequence of the Se layers ABCA|CABC|BCAB) with Moct (= 0.56 Mn + 0.44 In) in octahedral coordination (Moct,–Se = 6 × 2.721(1) A) and Mtet (= 0.78 In + 0.22 Mn) in tetrahedral coordination (Mtet-Se = 1 × 2.527(2) and 3 × 2.593(1) Å). The overall layer sequences is ΑβΒαCyA| Cα AγBβC| BγCβAα B.

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Dimer rattling mode induced low thermal conductivity in an excellent acoustic conductor

Nature Communications ◽

10.1038/s41467-020-19044-w ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Ji Qi ◽

Baojuan Dong ◽

Zhe Zhang ◽

Zhao Zhang ◽

Yanna Chen ◽

...

Keyword(s):

Thermal Conductivity ◽

Single Crystals ◽

Layered Structure ◽

First Principles ◽

Sound Speed ◽

Lattice Dynamics ◽

Room Temperature ◽

Lattice Thermal Conductivity ◽

Atomic Structures ◽

Order Of Magnitude

Abstract A solid with larger sound speeds usually exhibits higher lattice thermal conductivity. Here, we report an exception that CuP2 has a quite large mean sound speed of 4155 m s−1, comparable to GaAs, but single crystals show very low lattice thermal conductivity of about 4 W m−1 K−1 at room temperature, one order of magnitude smaller than GaAs. To understand such a puzzling thermal transport behavior, we have thoroughly investigated the atomic structures and lattice dynamics by combining neutron scattering techniques with first-principles simulations. This compound crystallizes in a layered structure where Cu atoms forming dimers are sandwiched in between P atomic networks. In this work, we reveal that Cu atomic dimers vibrate as a rattling mode with frequency around 11 meV, which is manifested to be remarkably anharmonic and strongly scatters acoustic phonons to achieve the low lattice thermal conductivity.

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Mechanical and thermal properties of single crystals of ZrB2

MRS Proceedings ◽

10.1557/proc-753-bb2.9 ◽

2002 ◽

Vol 753 ◽

Cited By ~ 1

Author(s):

N. L. Oka moto ◽

M. Kusakari ◽

K. Tanaka ◽

H. Inui ◽

M. Yamaguchi ◽

...

Keyword(s):

Plastic Deformation ◽

Thermal Expansion ◽

Single Crystals ◽

Elastic Constants ◽

Layered Structure ◽

Mechanical And Thermal Properties ◽

Slip Systems ◽

Compression Tests ◽

Deformation Behaviors ◽

Temperature Ranges

ABSTRACTCoefficients of thermal expansion (CTE), elastic constants and plastic deformation behaviors of single crystals of ZrB2, which possesses a hexagonal layered structure where pure Zr and pure B atomic planes stack alternatively along the c-axis, have been investigated in wide temperature ranges. While the observed elastic constants indicate highly anisotropic nature of atomic bonding being consistent with the layered structure, the observed CTE values are rather isotropic. Two operative slip systems, (0001)<1120> and on {1100}<1123>, are identified in compression tests. The observed plastic behaviors are discussed in the light of the deduced anisotropy in atomic bonding.

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