scholarly journals Dielectric properties of the system: 4-n-pentyloxybenzoic acid– N-(4-n-butyloxybenzylidene)-4᾽-methylaniline

2021 ◽  
Vol 16 (2) ◽  
pp. 138-147
Author(s):  
S. A. Syrbu ◽  
M. S. Fedorov ◽  
E. A. Lapykina ◽  
V. V. Novikov
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Anisotropy ◽  
Specific Electrical Conductivity ◽  
Conductivity Anisotropy ◽  
Independent Molecules ◽  
System Properties ◽  
The Individual

Objectives. Our aim was to study the dielectric properties of the 4-n-pentyloxybenzoic acid– N-(4-n-butyloxybenzylidene)-4’-methylaniline system and reveal how different concentrations of N-(4-n-butyloxybenzylidene)-4’-methylaniline additives affect the dielectric properties of 4-n-pentyloxybenzoic acid.Methods. System properties were investigated using polarization thermomicroscopy and dielcometry.Results. We found that dielectric anisotropy changes its sign from positive to negative at the transition temperature of the high-temperature nematic subphase to the low-temperature one. The anisotropy of the dielectric constant of N-4-n-butoxybenzylidene-4’-methylaniline has a positive value and increases as to the system approaches the crystalline phase. The crystal structure of the 4-n-pentyloxybenzoic acid contains dimers formed by two independent molecules due to a pair of hydrogen bonds. The crystal structure of N-(4-n-butoxybenzylidene)-4’-methylaniline contains associates formed by orientational interactions of two independent molecules. 4-n-Pentyloxybenzoic acid dimers (270 nm) and associates of N-4-n-butoxybenzylidene-4’- methylaniline (250 nm) proved to have approximately the identical length. Considering the close length values of the structural units of both compounds and the dielectric anisotropy sign, we assume that the N-4-n-butoxybenzylidene-4’-methylaniline associates are incorporated into the supramolecular structure of the 4-n-pentyloxybenzoic acid. The specific electrical conductivity of the compounds under study lies between 10−7 and 10−12 S∙cm−1. The relationship between the specific electrical conductivity anisotropy and the system composition in the nematic phase at the identical reduced temperature, obtained between 100 and 1000 Hz is symbatic. However, the electrical conductivity anisotropy values of the system obtained at 1000 Hz are lower compared to those obtained at 100 Hz. At N-(4-n-butoxybenzylidene)-4’-methylaniline concentrations between 30 and 60 mol %, the electrical conductivity anisotropy values are higher than those of the individual component.Conclusions. A change in the sign of the dielectric constant anisotropy of the 4-n-pentyloxybenzoic acid during nematic subphase transitions was established. We showed that the system has the highest dielectric constant anisotropy value when components have an equal number of moles. Highest electrical conductivity anisotropy values are observed when the concentration of the N-4-n-butoxybenzylidene-4᾽-methylaniline system lies between 30 and 60 mol %. 

Synthesis and Dielectric Properties of [(K0.5Na0.5)0.935Li0.065]NbO3 Added with Mn for Piezoelectric Ceramic

2016 ◽  
Vol 675-676 ◽  
pp. 635-638
Author(s):  
Jukkrit Kongphimai ◽  
Hassakorn Wattanasarn ◽  
Tosawat Seetawan
Keyword(s):  
Crystal Structure ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Physical Properties ◽  
Crystallite Size ◽  
Piezoelectric Ceramic ◽  
Theoretical Density ◽  
Milling Method ◽  
Xrd Patterns

[(K0.5Na0.5 )0.935Li0.065]NbO3–Mn ceramics (Mn = 0, 1.50 and 3 mol %) (KNNL–Mn) were synthesized and measured dielectric properties. Which the K2CO3, Na2CO3, Li2CO3, Nb2O5 and MnO2 (0, 1.5, 3 mol%) were mixed by ball milling method and calcined powders at 1,073 K for 4 h and the sintered at 1,343 K for 2 h in air. The crystal structure was analyzed by XRD technique, the crystallite size was identified by Scherrer’s equation and calculated the theoretical density. It was found that, the XRD patterns of the KNNL–Mn ceramics added with Mn contents was indicated the tetragonal structure and. the crystallite size of Mn = 0, 1.50 and 3 mol% about 32 nm, 34 nm and 57 nm, respectively. The physical properties of the KNNL–Mn ceramics was found that the maximum theoretical density of 90.79 % for Mn = 1.50 mol%. The dielectric constant was found to be maximum of 909.77 and dielectric loss of 0.48 for Mn = 3 mol%.

scholarly journals Fabrication and studying the dielectric properties of (polystyrene-copper oxide) nanocomposites for piezoelectric application

2019 ◽  
Vol 8 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Dalal Hassan ◽  
Ahmed Hashim Ah-yasari
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Copper Oxide ◽  
Electrical Resistance ◽  
Copper Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Increase With Increase

The preparation of (polystyrene-copper oxide) nanocomposites have been investigated for piezoelectric application. The copper oxide nanoparticles were added to polystyrene by different concentrations are (0, 4, 8 and 12) wt.%. The structural and A.C electrical properties of (PS-CuO) nanocomposites were studied. The results showed that the dielectric constant and dielectric loss of (PS-CuO) nanocomposites decrease with increase in frequency. The A.C electrical conductivity increases with increase in frequency. The dielectric constant, dielectric loss and A.C electrical conductivity of polystyrene increase with increase in copper oxide nanoparticles concentrations. The results of piezoelectric application showed that the electrical resistance of (PS-CuO) nanocomposites decreases with increase in pressure.

scholarly journals The crystal structure of 1-(2-hydroxy-5-methoxyphenyl)ethanone 4,4-dimethylthiosemicarbazone

2015 ◽  
Vol 71 (11) ◽  
pp. o811-o812
Author(s):  
Brian J. Anderson ◽  
Michael B. Freedman ◽  
Victoria A. Smolenski ◽  
Jerry P. Jasinski
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Methyl Groups ◽  
Asymmetric Unit ◽  
Compound C ◽  
Thioamide Group ◽  
The Mean ◽  
Independent Molecules ◽  
The Individual

The asymmetric unit of the title compound, C12H17N3O2S, contains two independent molecules,AandB. Both molecules are nearly planar with the dihedral angle between the mean planes of the thioamide group and benzene ring being 7.5 (1)° inAand 4.3 (2)° inB. In each molecule, the hydroxy group participates in intramolecular O—H...N hydrogen bonding, while the amino H atom is not involved in hydrogen bonding because of the steric hinderence caused by two neighboring methyl groups. In the crystal, the individual molecules are linked by weak C—H...O hydrogen bonds, formingA–AandB–Binversion dimers. The dimers are linkedviaC—H...π interactions which help stabilize the packing.

scholarly journals Crystal structure of 2-methyl-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one

2015 ◽  
Vol 71 (2) ◽  
pp. o123-o124 ◽  
Author(s):  
Preetika Sharma ◽  
K. N. Subbulakshmi ◽  
B. Narayana ◽  
K. Byrappa ◽  
Rajni Kant
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Asymmetric Unit ◽  
Π Interactions ◽  
Compound C ◽  
Independent Molecules ◽  
The Individual

The asymmetric unit of the title compound, C9H7NO2S, contains two crystallographically independent molecules (AandB). Both molecules are almost planar [maximum deviations = 0.047 (1) and 0.090 (1) Å, respectively, for the S atoms] with the oxazole and thiophene rings being inclined to one another by 2.65 (16)° in moleculeAand by 4.55 (15)° in moleculeB. In the crystal, the individual molecules are linkedviaC—H...O hydrogen bonds, forming –A–B–A–B– chains along the [10-1] direction. The chains are linkedviaC—H...π and π–π interactions [intercentroid distances = 3.767 (2) and 3.867 (2) Å] involving inversion-related oxazole and thiophene rings in both molecules, forming a three-dimensional structure.

Structural and Dielectric Properties of XBaZr0.2Ti0.8O3-(1-x)BiFeO3 Solid Solution Ceramics

2014 ◽  
Vol 787 ◽  
pp. 261-266
Author(s):  
Wei Cai ◽  
Shi Xing Zhong ◽  
Chun Lin Fu ◽  
Gang Chen ◽  
Xiao Ling Deng
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Solid State Reaction Method ◽  
Barium Zirconate ◽  
Conventional Solid State Reaction ◽  
Barium Zirconate Titanate ◽  
Zirconate Titanate

xBaZr0.2Ti0.8O3-(1-x)BiFeO3(x=0, 0.3, 0.5, 0.7) solid solution ceramics were prepared by conventional solid-state reaction method. The crystal structure and dielectric properties ofxBaZr0.2Ti0.8O3-(1-x)BiFeO3ceramics have been investigated. The result indicates that the crystal structure of solid solution ceramics changes from rhobohedral to pseudocubic structure with the increase of barium zirconate titanate content. The room temperature dielectric constant of all samples decreases with the increasing of frequency. When the temperature is in the range of 30oC~150oC, the dielectric constant of all samples increases as temperature rises. In the same temperature range, the dielectric loss of BiFeO3ceramics increases with the rise of temperature and the dielectric loss ofxBaZr0.2Ti0.8O3-(1-x)BiFeO3(x=0.3~0.7) changes a little. The addition of barium zirconate titanate leads to the decrease of dielectric loss and leakage current for BiFeO3ceramics.

scholarly journals Analysis of X-ray structure, dielectric properties and AC conductivity of (4E)-2-amino-3-cyanobenzo[b]oxocin-6-one

2016 ◽  
Vol 34 (2) ◽  
pp. 386-392 ◽  
Author(s):  
H.A.M. Ali ◽  
Magdy A. Ibrahim
Keyword(s):  
Crystal Structure ◽  
Activation Energy ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Relaxation Time ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Ac Electrical Conductivity ◽  
X Ray ◽  
Different Temperatures

AbstractThe crystal structure of (4E)-2-amino-3-cyanobenzo[b]oxocin-6-one, denoted as 4(E)-ACBO, was analyzed using X-ray diffraction technique. The dielectric and AC electrical conductivity measurements of the bulk 4(E)-ACBO in the form of pellet were studied in the range of frequency 42 Hz to 5 MHz and the temperature range of 303 K to 373 K. The temperature and frequency dependence of dielectric constant (∊1), dielectric loss (∊2) and AC electrical conductivity (σAC) were investigated. The relaxation time (τ) for electrons to hop over a barrier of height WH was calculated at different temperatures. The AC activation energy was determined from the temperature dependence of σAC at different frequencies.

scholarly journals N′-(1,3-Benzothiazol-2-yl)benzenesulfonohydrazide: crystal structure, Hirshfeld surface analysis and computational chemistry

2019 ◽  
Vol 75 (4) ◽  
pp. 516-523
Author(s):  
Thomas C. Baddeley ◽  
Marcus V. N. de Souza ◽  
James L. Wardell ◽  
Mukesh M. Jotani ◽  
Edward R. T. Tiekink
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Intermolecular Interactions ◽  
Torsion Angles ◽  
Axis Direction ◽  
Compound C ◽  
Phenyl Rings ◽  
Independent Molecules ◽  
The Individual ◽  
A Minor

The asymmetric unit of the title compound, C13H11N3O2S2, comprises two independent molecules (A and B); the crystal structure was determined by employing synchrotron radiation. The molecules exhibit essentially the same features with an almost planar benzothiazole ring (r.m.s. deviation = 0.026 and 0.009 Å for A and B, respectively), which forms an inclined dihedral angle with the phenyl ring [28.3 (3) and 29.1 (3)°, respectively]. A difference between the molecules is noted in a twist about the N—S bonds [the C—S—N—N torsion angles = −56.2 (5) and −68.8 (5)°, respectively], which leads to a minor difference in orientation of the phenyl rings. In the molecular packing, A and B are linked into a supramolecular dimer via pairwise hydrazinyl-N—H...N(thiazolyl) hydrogen bonds. Hydrazinyl-N—H...O(sulfonyl) hydrogen bonds between A molecules assemble the dimers into chains along the a-axis direction, while links between centrosymmetrically related B molecules, leading to eight-membered {...HNSO}2 synthons, link the molecules along [001]. The result is an undulating supramolecular layer. Layers stack along the b-axis direction with benzothiazole-C—H...O(sulfonyl) points of contact being evident. The analyses of the calculated Hirshfeld surfaces confirm the relevance of the above intermolecular interactions, but also serve to further differentiate the weaker intermolecular interactions formed by the independent molecules, such as π–π interactions. This is also highlighted in distinctive energy frameworks calculated for the individual molecules.

Analytical description of sodium halogenides melts specific electric conductivity and its calculation for sodium astatide melt

2019 ◽  
Vol 60 (12) ◽  
pp. 125-132
Author(s):  
Ivan K. Garkushin ◽  
◽  
Olga V. Lavrenteva ◽  
Karina R. Gilmanova ◽  
Yana A. Andreeva ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Comparative Analysis ◽  
Ionic Radius ◽  
Specific Conductivity ◽  
Analytical Description ◽  
Specific Electrical Conductivity ◽  
Specific Electric Conductivity ◽  
Straight Line ◽  
Direct Equation ◽  
The Individual

The paper presents analytical and graphical dependences of the individual haloganides melts specific electrical conductivity æ of the sodium NaHal series (Hal – F, Cl, Br, I) on the halogen order number Z, ionic radius r of haloganide-ion Hal–, halogen ionic potential 1/r, reduced ionic radius r/Z, difference of electronegativity (∆χ = χ(Hal) – χ(Na)): æ = f(Z); æ = f(r); æ = f(1/r); æ = f(r/Z); æ = f(∆χ) for the temperature higher melting temperatures on 5, 10, 50, 75, 100, 150 и 200°. M.Kh. Karapetyans сomparative methods were applied for the description. The minimum standard deviation and maximum correlation coefficient corresponds to the equation æ–1 = a + bexp1/r, according to which the numerical values of æ(NaAt) are calculated for real temperatures. The temperature dependence æ of the NaAt melt is described by the equation æ = 0.0508+0.0023Т. A comparative analysis of the relationship between the specific electrical conductivity of NaHal melts at a temperature of Tm + n (n = 10 ... 200° higher the melting temperature) and æ at (Tm + 5°). A comparative analysis is represented by straightforward dependencies. It was shown that the specific electrical conductivity of the NaAt melt is related to the electrical conductivity of LiAt by the direct equation æ(NaAt) = 0.035+0.607æ(LiAt). The straight line equationalso relates æ of the NaHal melt (Hal – F, Br, I, At) to the specific conductivity of the NaCl melt. Between the numerical values of the specific electrical conductivity of the sodium astatide (NaAt) melt calculated by different methods, consistent data were obtained.

Comparative Study on Electrical and Dielectric Properties of Sintered Nano and Micro Silicon Nitride Ceramics

2016 ◽  
Vol 2 (1) ◽  
pp. 13-18
Author(s):  
Imran Khan ◽  
M S A Khan
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Silicon Nitride ◽  
Dc Conductivity ◽  
Temperature Range ◽  
Nitride Ceramics ◽  
Electrical And Dielectric Properties ◽  
Sintered Silicon

In the present work we have studied the electrical conductivity, dielectric constant and dielectric loss of Sintered Silicon Nitride ceramics. In this study it was found that the grain size has great impact on electrical conductivity and dielectric properties of Sintered Silicon Nitride Ceramics. The result shows more efficiency of electrical and dielectric properties with nano sized grains.  The sintering was performed in a programmable furnace at 950 K. The dc conductivity measured in the temperature range 300 K to 900 K. At higher temperature (T > 800 K), the dc conductivity increases exponentially with temperature for both of the investigated samples. Dielectric constant and loss are measured in the temperature range 300 K to 900 K with frequency range 1 KHz to 1 MHz. To confirm the grain size, the samples are characterized by the Scanning Electron Microscope (SEM). These types of samples can be used as a high temperature semi-conducting materials.

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