Predicted low thermal conductivities in antimony films and the role of chemical functionalization

2016 ◽  
Vol 18 (43) ◽  
pp. 30061-30067 ◽  
Author(s):  
Tian Zhang ◽  
Yuan-Yuan Qi ◽  
Xiang-Rong Chen ◽  
Ling-Cang Cai
Keyword(s):  
Crystal Structure ◽  
Thermal Transport ◽  
Effective Means ◽  
Two Dimensional ◽  
Chemical Functionalization ◽  
Thermal Conductivities

Chemical functionalization is an effective means of tuning the electronic and crystal structure of a two-dimensional material, but very little is known regarding the correlation between thermal transport and chemical functionalization.

scholarly journals Observation of second sound in graphite at temperatures above 100 K

Science ◽  
2019 ◽  
Vol 364 (6438) ◽  
pp. 375-379 ◽  
Author(s):  
S. Huberman ◽  
R. A. Duncan ◽  
K. Chen ◽  
B. Song ◽  
V. Chiloyan ◽  
...  
Keyword(s):  
Thermal Transport ◽  
Low Temperatures ◽  
Practical Importance ◽  
Layered Materials ◽  
Optical Measurements ◽  
Two Dimensional ◽  
Second Sound ◽  
Rare Occurrence ◽  
Time Resolved

Wavelike thermal transport in solids, referred to as second sound, is an exotic phenomenon previously limited to a handful of materials at low temperatures. The rare occurrence of this effect restricted its scientific and practical importance. We directly observed second sound in graphite at temperatures above 100 kelvins by using time-resolved optical measurements of thermal transport on the micrometer-length scale. Our experimental results are in qualitative agreement with ab initio calculations that predict wavelike phonon hydrodynamics. We believe that these results potentially indicate an important role of second sound in microscale transient heat transport in two-dimensional and layered materials in a wide temperature range.

Structural role of tellurium in the minerals of the pearceite-polybasite group

2013 ◽  
Vol 77 (4) ◽  
pp. 419-428 ◽  
Author(s):  
L. Bindi ◽  
P. Voudouris ◽  
P. G. Spry
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Atomic Displacement ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dimensional Diffusion ◽  
Diffusion Paths ◽  
Linear Coordination

AbstractThe crystal structure of a Te-rich polybasite has been refined by means of X-ray diffraction data collected at room temperature (space group Pm1; R = 0.0505 for 964 observed reflections and 94 parameters; refined formula Ag14.46Cu1.54Sb1.58As0.42S9.67Te1.33). The structure comprises stacking of [(Ag, Cu)6(Sb, As)2(S, Te)7]2–A and [Ag9Cu(S, Te)2(S, Te)2]2+B layer modules in which Sb forms isolated SbS3 pyramids, as occurs typically in sulfosalts, Cu links two S atoms in a linear coordination and Ag occupies sites with coordination ranging from quasi linear to almost tetrahedral. The silver d10 ions are found in the B layer module along two-dimensional diffusion paths and their electron densities evidenced by means of a combination of a Gram-Charlier development of the atomic displacement factors and a split model. The Te-for-S substitution occurs at the same structural sites that Se substitutes for S in selenopolybasite and the Te occupancy at one of these sites is 0.49, thus suggesting the possibility that 'telluropolybasite' could be found in nature.

Role of halogen–halogen contacts in the crystal structures of three new solvates of the drug oxyclozanide

2017 ◽  
Vol 73 (12) ◽  
pp. 1056-1063
Author(s):  
Balasubramanian Sridhar ◽  
Krishnan Ravikumar
Keyword(s):  
Crystal Structure ◽  
Domestic Animals ◽  
Intensity Data ◽  
Two Dimensional ◽  
Halogen Bonds ◽  
One Dimensional ◽  
Ideal Candidate ◽  
Intermolecular Contacts ◽  
Solvent Molecules

Halogen–halogen contacts are electrostatic in nature and exhibit directionality similar to hydrogen bonds. Oxyclozanide [systematic name: 2,3,5-trichloro-N-(3,5-dichloro-2-hydroxyphenyl)-6-hydroxybenzamide] is a drug used for the treatment of fascioliasis in domestic animals. The molecule carries five chlorine substituents and represents an ideal candidate for the study of halogen bonds in the crystal. Three new crystalline solvates of oxyclozanide, namely, oxyclozanide benzene hemisolvate, C13H6Cl5NO3·0.5C6H6, (I), oxyclozanide xylene hemisolvate, C13H6Cl5NO3·0.5C8H10, (II), and oxyclozanide toluene hemisolvate, C13H6Cl5NO3·0.5C7H8, (III), were structurally characterized. In this context, the crystal structure of oxyclozanide chlorobenzene hemisolvate, C13H6Cl5NO3·0.5C6H5Cl, (IV), was redetermined based on intensity data collected at 100 K. In all four solvates, the cocrystallized solvent molecules are located on crystallographic inversion centres. Solvates (I)–(IV) exhibit similar one-dimensional hydrogen-bonded chains generated by O—H...O, O—H...Cl and Cl...Cl interactions. The extension of these one-dimensional chains into two-dimensional layers is promoted by Cl...Cl and C—H...π contacts. Solvates (III) and (IV) are isostructural and differ from (I) and (II) with respect to subtle details concerning the intermolecular contacts.

scholarly journals Ferromagnetism and giant magnetoresistance in zinc-blende FeAs monolayers embedded in semiconductor structures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Le Duc Anh ◽  
Taiki Hayakawa ◽  
Yuji Nakagawa ◽  
Hikari Shinya ◽  
Tetsuya Fukushima ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Curie Temperature ◽  
First Principles ◽  
Giant Magnetoresistance ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Semiconductor Structures ◽  
Zinc Blende ◽  
Quantum Ground States

AbstractMaterial structures containing tetrahedral FeAs bonds, depending on their density and geometrical distribution, can host several competing quantum ground states ranging from superconductivity to ferromagnetism. Here we examine structures of quasi two-dimensional (2D) layers of tetrahedral Fe-As bonds embedded with a regular interval in a semiconductor InAs matrix, which resembles the crystal structure of Fe-based superconductors. Contrary to the case of Fe-based pnictides, these FeAs/InAs superlattices (SLs) exhibit ferromagnetism, whose Curie temperature (TC) increases rapidly with decreasing the InAs interval thickness tInAs (TC ∝ tInAs−3), and an extremely large magnetoresistance up to 500% that is tunable by a gate voltage. Our first principles calculations reveal the important role of disordered positions of Fe atoms in the establishment of ferromagnetism in these quasi-2D FeAs-based SLs. These unique features mark the FeAs/InAs SLs as promising structures for spintronic applications.

scholarly journals Crystal structure and thermoelectric properties of Sr–Mo substituted CaMnO3: a combined experimental and computational study

2015 ◽  
Vol 3 (47) ◽  
pp. 12245-12259 ◽  
Author(s):  
D. Srivastava ◽  
F. Azough ◽  
R. Freer ◽  
E. Combe ◽  
R. Funahashi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermoelectric Properties ◽  
Thermal Transport ◽  
Computational Study ◽  
Domain Boundaries ◽  
Co Doped

Experimental and modelling investigation of Sr/Mo (co-)doped CaMnO3 highlighted the role of Mn3+ and presence of domain boundaries in thermal transport and thermoelectric properties.

The State versus the People

2020 ◽  
Author(s):  
Matthew Rendle
Keyword(s):  
French Revolution ◽  
Effective Means ◽  
State Control ◽  
Scarce Resources ◽  
Soviet State ◽  
The People ◽  
Wide Range ◽  
Complex Picture ◽  
The Military

This book provides the first detailed account of the role of revolutionary justice in the early Soviet state. Law has often been dismissed by historians as either unimportant after the October Revolution amid the violence and chaos of civil war or even, in the absence of written codes and independent judges, little more than another means of violence. This is particularly true of the most revolutionary aspect of the new justice system, revolutionary tribunals—courts inspired by the French Revolution and established to target counter-revolutionary enemies. This book paints a more complex picture. The Bolsheviks invested a great deal of effort and scarce resources into building an extensive system of tribunals that spread across the country, including into the military and the transport network. At their peak, hundreds of tribunals heard hundreds of thousands of cases every year. Not all ended in harsh sentences: some were dismissed through lack of evidence; others given a wide range of sentences; others still suspended sentences; and instances of early release and amnesty were common. This book, therefore, argues that law played a distinct and multifaceted role for the Bolsheviks. Tribunals stood at the intersection between law and violence, offering various advantages to the Bolsheviks, not least strengthening state control, providing a more effective means of educating the population on counter-revolution, and enabling a more flexible approach to the state’s enemies. All of this adds to our understanding of the early Soviet state and, ultimately, of how the Bolsheviks held on to power.

scholarly journals Rational Design and Simulation of Two-Dimensional Perovskite Photonic Crystal Absorption Layers Enabling Improved Light Absorption Efficiency for Solar Cells

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2460
Author(s):  
Jian Zou ◽  
Mengnan Liu ◽  
Shuyu Tan ◽  
Zhijie Bi ◽  
Yong Wan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solar Cells ◽  
Photonic Crystal ◽  
Incident Light ◽  
Absorption Efficiency ◽  
Utilization Efficiency ◽  
Photonic Crystal Structure ◽  
Two Dimensional ◽  
Photoelectric Conversion ◽  
Absorption Layer

A two-dimensional perovskite photonic crystal structure of Methylamine lead iodide (CH3NH3PbI3, MAPbI3) is rationally designed as the absorption layer for solar cells. The photonic crystal (PC) structure possesses the distinct “slow light” and band gap effect, leading to the increased absorption efficiency of the absorption layer, and thus the increased photoelectric conversion efficiency of the battery. Simulation results indicate that the best absorption efficiency can be achieved when the scattering element of indium arsenide (InAs) cylinder is arranged in the absorption layer in the form of tetragonal lattice with the height of 0.6 μm, the diameter of 0.24 μm, and the lattice constant of 0.4 μm. In the wide wavelength range of 400–1200 nm, the absorption efficiency can be reached up to 82.5%, which is 70.1% higher than that of the absorption layer without the photonic crystal structure. In addition, the absorption layer with photonic crystal structure has good adaptability to the incident light angle, presenting the stable absorption efficiency of 80% in the wide incident range of 0–80°. The results demonstrate that the absorption layer with photonic crystal structure can realize the wide spectrum, wide angle, and high absorption of incident light, resulting in the increased utilization efficiency of solar energy.

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