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InterConf ◽  
2021 ◽  
pp. 202-220
Author(s):  
Koba Amirkhanashvili ◽  
Alexandre Sobolev ◽  
Vladimer Tsitsishvili ◽  
Nani Zhorzholiani

The present paper reports on the synthesis and structure of bis(2-(diethylamino)-N-(2,6-dimethylphenyl)acetamide) or bis(lidocaine) tetrachloridocuprate(II). The complex with the formula (C14H23ON2)2CuCl4 (or (LidH)2[CuCl4]), crystallizes in the monoclinic space group P21/c with a = 15.7831(2), b = 24.2992(2), c = 17.8748(2) Å, β = 104.874(1)°,V = 6625.58(13) Å3, Z = 8, and Dc = 1.355 Mg/m3. The coordination of the Cu2+ ions with chlorine atoms generates two differently distorted tetrahedral anions [CuCl4]2–, while four protonated cations LidH+ remain in an outer coordination sphere. Anions and cations are associated by hydrogen bonds of the N–H···Cl type to form the 2((LidH)2[CuCl4]) dimer, in which the distance between two copper atoms is 8.95 Å. With the help of hydrogen bonds of the type N–H···O and N–H···Cl, each dimer is connected with four neighboring dimers, resulting in a three-dimensional structure in which dimers lie at an angle of 28.39° to the a crystallographic axis in the ab planes located at a distance of 10.67 Å from each other.


Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5626 ◽  
Author(s):  
Ana Arauzo ◽  
Elena Bartolomé ◽  
Javier Luzón ◽  
Pablo Alonso ◽  
Angelica Vlad ◽  
...  

We present the magnetic properties of the metal-organic framework {[CoCxAPy]·2.15 H2O}n (Cx = bis(carboxypropyl)tetramethyldisiloxane; APy = 4,4`-azopyridine) (1) that builds up from the stacking of 2D coordination polymers. The 2D-coordination polymer in the bc plane is formed by the adjacent bonding of [CoCxAPy] 1D two-leg ladders with Co dimer rungs, running parallel to the c-axis. The crystal packing of 2D layers shows the presence of infinite channels running along the c crystallographic axis, which accommodate the disordered solvate molecules. The Co(II) is six-coordinated in a distorted octahedral geometry, where the equatorial plane is occupied by four carboxylate oxygen atoms. Two nitrogen atoms from APy ligands are coordinated in apical positions. The single-ion magnetic anisotropy has been determined by low temperature EPR and magnetization measurements on an isostructural compound {[Zn0.8Co0.2CxAPy]·1.5 CH3OH}n (2). The results show that the Co(II) ion has orthorhombic anisotropy with the hard-axis direction in the C2V main axis, lying the easy axis in the distorted octahedron equatorial plane, as predicted by the ab initio calculations of the g-tensor. Magnetic and heat capacity properties at very low temperatures are rationalized within a S* = 1/2 magnetic dimer model with anisotropic antiferromagnetic interaction. The magnetic dimer exhibits slow relaxation of the magnetization (SMM) below 6 K in applied field, with a tlf ≈ 2 s direct process at low frequencies, and an Orbach process at higher frequencies with U/kB = 6.7 ± 0.5 K. This compound represents a singular SMM MOF built-up of Co-dimers with an anisotropic exchange interaction.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1985
Author(s):  
Luka Pirker ◽  
Bojana Višić ◽  
Janez Kovač ◽  
Srečo D. Škapin ◽  
Maja Remškar

WnO3n−1 nanotiles, with multiple stoichiometries within one nanotile, were synthesized via the chemical vapour transport method. They grow along the [010] crystallographic axis, with the thickness ranging from a few tens to a few hundreds of nm, with the lateral size up to several µm. Distinct surface corrugations, up to a few 10 nm deep appear during growth. The {102}r crystallographic shear planes indicate the WnO3n−1 stoichiometries. Within a single nanotile, six stoichiometries were detected, namely W16O47 (WO2.938), W15O44 (WO2.933), W14O41 (WO2.928), W13O38 (WO2.923), W12O35 (WO2.917), and W11O32 (WO2.909), with the last three never being reported before. The existence of oxygen vacancies within the crystallographic shear planes resulted in the observed non-zero density of states at the Fermi energy.


Author(s):  
A.Ch. Matiyev ◽  
R.T. Uspazhiev

Based on the performed studies, it was found that tensile deformation along the [1] crystallographic axis of TlInSe2 crystals shifts the energy of indirect transitions to the short-wavelength region, and the compression deformation, on the contrary, to the long-wavelength region.


Author(s):  
A.Ch. Matiyev ◽  
R.T. Uspazhiev

Based on the study of the dependence (, it was shown that the current in the nonlinear region (taking into account the thermal-field effect of Poole-Frenkel) is due to a weak field effect, both when measured in parallel and perpendicular to the crystallographic axis crystal TlFeS2. The calculated values of the concentration of ionized centers Nt, the mean free path λ, and the values of the Frenkel coefficient in the shape of a potential well in TlFeS2 crystals have been determined.


Author(s):  
V.A. Trush ◽  
◽  
N.S. Kariaka ◽  
I.S. Konovalova ◽  
S.V. Shishkina ◽  
...  

N-(dimethoxyphosphoryl)-1-methylpyridinium-4-carboximidate, a new carbacylamidophosphate-type compound, was synthesized and characterized by means of IR, 1H and 31P NMR and UV-Vis spectroscopies and X-ray analysis. The molecule of the synthesized compound has triclinic (P-1) symmetry, displays monomeric motif in crystal and crystalizes as solvate containing methanol molecule, which is connected to carbacylamidophosphate molecule through O(2)H(5A)–O(5) hydrogen bond. Through – stacking interactions, the molecules of the synthesized compound are linked in the chain along the a crystallographic axis. Several other intermolecular bonds connect these chains along b and c crystallographic axes. The intermolecular interactions with HH and OH contacts prevail in the crystalline structure of N-(dimethoxyphosphoryl)-1-methylpyridinium-4-carboximidate, the contribution of planar stacking CC contacts being equal to 4.1%. The synthesized compound was found to be well soluble in water. By using computer program PASS, we established that the synthesized substance is likely can exhibit 18 types of biological activity in experiment.


2021 ◽  
Vol 316 ◽  
pp. 193-200
Author(s):  
Valery Lebedev ◽  
Y.M. Vernigorov ◽  
L.V. Chunakhova

Anisotropy of a powder ferromagnetic product can be created by focusing separate particles in the direction of a certain crystallographic axis in a magnetic field. By fitting modes of electromagnetic field it is possible to regulate the intensity of clusters movement and powder particles, as well as to destroy clusters up to the separate particles. At the increase of constant magnetic field induction up to a certain value, typical for every material, the intensification of processes of secondary aggregation and formation of anisotropic layer structure takes place. A design model of magneto-vibrational state of finely divided powder suggested in the article enables to calculate the parameters of electromagnetic field, which provide optimal characteristics of a powder product. It has been shown that, at a certain ratio of parameters of electromagnetic field in a dispersive ferromagnetic medium, a chain system is formed. The chains are focused along magnetic-field lines and execute a vibration in a variable inhomogeneous magnetic field, according to the law of a string with fixed ends.


2021 ◽  
Vol 46 (6) ◽  
pp. 1490
Author(s):  
Nicolas Poulvellarie ◽  
Carlos Mas Arabi ◽  
Charles Ciret ◽  
Sylvain Combrié ◽  
Alfredo De Rossi ◽  
...  

2021 ◽  
Author(s):  
Benyahia El-Hachemi ◽  
Sebais Miloud ◽  
Mammeri Sabah ◽  
Touahri Souad ◽  
Ouili Zineddine ◽  
...  

Abstract ZnTe nanoparticles (NPs) were synthesized using hydrothermal method and then were dispersed in poly(vinyl-chloride) (PVC) to prepare hybrid PVC/ZnTe nanocomposite thin films which were deposited on glass substrates by the dip coating technique. Structural, optical and electrical properties of films were investigated by different techniques. XRD analysis revealed that synthesized ZnTe NPs have a cubic structure and a nanoscale size,while pure PVC films have a weak degree of crystallinity and exhibit a broad diffraction peak at low angles. The PVC/ZnTe nanocomposite thin films display an intense diffraction peak corresponding to the plane (220) which indicates a preferred orientation of ZnTe nanocystallites along crystallographic axis [220]. This texture was also showed by the atomic force microscopy micrographs.The analysis by FT-IR and Raman vibrational spectroscopies confirmed the incorporation of ZnTe NPs in the PVC matrix.The ZnTe/PVC nanocomposites thin films have an optical transparency over 80 % in the visible range and an optical gap close to 4.07 eV. Discrepancies with respect to the gap of pure PVC (red shift) and bulk ZnTe (blue shift) are due to the effect of the interaction between the ZnTe NPsand the PVC matrixand alsoto the nanometric size of the ZnTe crystallites. Photoluminescence (PL) spectra showed an enhanced blue emission at 466 nm,a green emissionat 522 nm and a strong red emission at 686 nm. Thus the incorporation of oriented ZnTe NPs induced a new optical behavior of the PVC polymer matrix.Electrical measurements indicate a decrease of electrical resistivity of PVC/ZnTe nanocompositesas ZnTe NPs concentration increases.


2021 ◽  
Vol 45 (1) ◽  
pp. 48-57
Author(s):  
M.V. Davidovich

We consider dissipative Dyakonov plasmon-polaritons as surface waves propagating along the plane boundary of a hyperbolic metamaterial with an arbitrary orientation of the crystallographic axis. Conditions for the existence of fast, slow, gliding flowing, forward and backward plasmon-polaritons are found. A waveguide in the form of an asymmetric layer of a hyperbolic metamaterial is also considered. An expression for the density of electromagnetic energy in such a metamaterial is given.


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