Solid solution Ca12Al14O33±δ: V5+, Mo5+

2019 ◽  
pp. 49-54
Author(s):  
A. S. Tolkacheva ◽  
S.  N. Shkerin ◽  
S. V. Plaksin ◽  
A. A. Pankratov ◽  
N. I. Moskalenko
Keyword(s):  
Solid Solution ◽  
Electrical Conductivity ◽  
Impedance Spectroscopy ◽  
Temperature Dependence ◽  
Charge State ◽  
Octahedral Coordination ◽  
Order Of Magnitude ◽  
Combination Of Methods

A solid solution of the composition Ca12–x(Al14Vx)O33+δ(0 ≤ х ≤ 0,07) was synthesized. A combination of methods established the charge state of vanadium in a solid solution. The principle of filling with a dopant crystallographic positions in the structure of mayenite is proposed: vanadium cations replace a small number of aluminum positions, presumably in octahedral coordination. The temperature dependence of the electrical conductivity of Ca11,93(Al14V0,07)O33+δ was studied by the impedance spectroscopy. It is shown that doping of mayenite with vanadium increases the value of electrical conductivity by an order of magnitude.

scholarly journals SYNTHESIS AND ELECTRICAL CONDUCTIVITY OF SOLID SOLUTIONS OF THE SYSTEM RbF-PbF2-SnF2

2019 ◽  
Vol 85 (5) ◽  
pp. 60-68
Author(s):  
Yuliay Pogorenko ◽  
Anatoliy Omel’chuk ◽  
Roman Pshenichny ◽  
Anton Nagornyi
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Solid Solutions ◽  
Basic Structure ◽  
Elementary Cell ◽  
Initial Structure ◽  
Fluoride Ions ◽  
Temperature Range ◽  
Order Of Magnitude

In the system RbF–PbF2–SnF2 are formed solid solutions of the heterovalent substitution RbxPb0,86‑xSn1,14F4-x (0 < x ≤ 0,2) with structure of β–PbSnF4. At x > 0,2 on the X-ray diffractograms, in addition to the basic structure, additional peaks are recorded that do not correspond to the reflexes of the individual fluorides and can indicate the formation of a mixture of solid solutions of different composition. For single-phase solid solutions, the calculated parameters of the crystal lattice are satisfactorily described by the Vegard rule. The introduction of ions of Rb+ into the initial structure leads to an increase in the parameter a of the elementary cell from 5.967 for x = 0 to 5.970 for x = 0.20. The replacement of a part of leads ions to rubium ions an increase in electrical conductivity compared with β–PbSnF4 and Pb0.86Sn1.14F4. Insignificant substitution (up to 3.0 mol%) of ions Pb2+ at Rb+ at T<500 K per order of magnitude reduces the conductivity of the samples obtained, while the nature of its temperature dependence is similar to the temperature dependence of the conductivity of the sample β-PbSnF4. By replacing 5 mol. % of ions with Pb2+ on Rb+, the fluoride ion conductivity at T> 450 K is higher than the conductivity of the initial sample Pb0,86Sn1,14F4 and at temperatures below 450 K by an order of magnitude smaller. With further increase in the content of RbF the electrical conductivity of the samples increases throughout the temperature range, reaching the maximum values at x≥0.15 (σ573 = 0.34–0.41 S/cm, Ea = 0.16 eV and σ373 = (5.34–8.16)•10-2 S/cm, Ea = 0.48–0.51 eV, respectively). In the general case, the replacement of a part of the ions of Pb2+ with Rb+ to an increase in the electrical conductivity of the samples throughout the temperature range. The activation energy of conductivity with an increase in the content of RbF in the low-temperature region in the general case increases, and at temperatures above 400 K is inversely proportional decreasing. The nature of the dependence of the activation energy on the concentration of the heterovalent substituent and its value indicate that the conductivity of the samples obtained increases with an increase in the vacancies of fluoride ions in the structure of the solid solutions.

scholarly journals Effect of zinc doping on electrical properties of LaAlO3 perovskite

2021 ◽  
Vol 8 (1) ◽  
pp. 20218103
Author(s):  
Anastasia V. Egorova ◽  
Ksenia G. Belova ◽  
Irina E. Animitsa ◽  
Yelizaveta A. Morkhova ◽  
Artem A. Kabanov
Keyword(s):  
Solid Solution ◽  
Electrical Conductivity ◽  
Density Functional ◽  
Electronic Conductivity ◽  
High Energy ◽  
Homogeneity Region ◽  
Partial Substitution ◽  
Cubic Symmetry ◽  
Order Of Magnitude ◽  
P Type

New solid solution with the general formula of LaAl1-xZnxO3-1/2x was prepared by a solid-state reaction route. According to XRD, the crystal structure of LaAlO3 is rhombohedral, while the solid solution possesses cubic symmetry. Homogeneity region of the solid solution LaAl1-xZnxO3-1/2x was narrow and limited to the maximum concentration of 5 mol. %. Computer simulations using crystalochemistry and density functional theory approaches showed that LaAlO3 has high energy barriers for O2–-ion transport (2.79 eV). These results are in good agreement with the low values of electrical conductivity obtained experimentally. The electrical conductivity of LaAl1-xZnxO3-1/2x was measured by impedance spectroscopy in the temperature range of 200–1000 °C. The partial substitution of Al3+ by Zn2+ was found to increase the electrical conductivity by ~2 order of magnitude. The electrical conductivity of doped phase LaAl0.95Zn0.05O2.975 as a function of oxygen partial pressure was measured, and the partial contributions (oxygen-ionic and electronic) were determined. It was found that the sample has mixed ionic and p-type electronic conductivity, while the electronic contribution increases with the rise of the temperature.

scholarly journals Fluoride ion conductivity of solid solutions KxPb0.86-xSn1.14F4-x

2021 ◽  
pp. 31-31
Author(s):  
Yuliia Pohorenko ◽  
Roman Pshenychnyi ◽  
Tamara Pavlenko ◽  
Anatoliy Omel’chuk ◽  
Volodymyr Trachevskyi
Keyword(s):  
Electrical Conductivity ◽  
Impedance Spectroscopy ◽  
Solid Solutions ◽  
Ion Conductivity ◽  
19F Nmr ◽  
Fluoride Ion ◽  
Fluoride Ions ◽  
Order Of Magnitude ◽  
Increasing Temperature

The electrical conductivity of solid solutions with tetragonal syngony formed in 0.86(xKF - (1-x)PbF2) - 1.14SnF2 systems has been studied by 19F NMR and impedance spectroscopy. It was found that the Pb0.86Sn1.14F4 phase is characterized by better values of fluoride-ion conductivity than the ?-PbSnF4 compound. It was found that the substitution of Pb2+ ions by K+ up to ? = 0.07 in the structure of Pb0.86Sn1.14F4 contributes to increase in electrical conductivity by an order of magnitude relative to the original Pb0.86Sn1.14F4. The sample of the composition K0.03Pb0.83Sn1.14F3.97 has the highest electrical conductivity (?600 = 0.38 S cm-1, ?330 = 0.01 S cm-1). The fluoride anions in the synthesized samples of KxPb0.86-xSn1.14F4-x solid solutions occupy three structurally nonequivalent positions. It is shown that with increasing temperature, there is a redistribution of fluorine anions between positions in the anion lattice, which results in an increase in the concentration of highly mobile fluoride ions, which determine the electrical conductivity of samples.

scholarly journals Суперионная проводимость твердых растворов (TlGaSe-=SUB=-2-=/SUB=-)-=SUB=-1-x-=/SUB=-(TlInS-=SUB=-2-=/SUB=-)-=SUB=-x-=/SUB=-

2018 ◽  
Vol 52 (10) ◽  
pp. 1111
Author(s):  
Р.М. Сардарлы ◽  
А.П. Абдуллаев ◽  
Н.А. Алиева ◽  
Ф.Т. Салманов ◽  
М.Ю. Юсифов ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid Solution ◽  
Electrical Conductivity ◽  
Impedance Spectroscopy ◽  
Complex Impedance ◽  
Relaxation Processes ◽  
Spectroscopy Technique ◽  
Abrupt Increase ◽  
Impedance Spectroscopy Technique ◽  
Frequency Dependences

AbstractSamples of (TlGaSe_2)_1 – _ x (TlInS_2)_ x solid solutions are synthesized. The frequency dependences (2 × 10^1–10^6 Hz) of components of the total complex impedance are studied by the impedance spectroscopy technique and relaxation processes are investigated depending on the composition of the (TlGaSe_2)_1 – _ x (TlInS_2)_ x solid solution in the solubility region ( x = 0–0.4). Corresponding diagrams on the ( Z ''– Z ') complex plane are analyzed using the equivalent substitutional circuit method. An anomaly in the temperature dependence of the electrical conductivity, which manifests itself in an abrupt increase in the conductivity, is found for the studied (TlGaSe_2)_1 – _ x (TlInS_2)_ x solid solution at 400 K. This peculiarity is associated with the phase transition into the superionic state.

Electrical Conductivity of Chloro(phenyl)glyoxime and Its Co(II), Ni(II) and Cu(II) Complexes

2003 ◽  
Vol 68 (7) ◽  
pp. 1233-1242 ◽  
Author(s):  
Orhan Turkoglu ◽  
Mustafa Soylak ◽  
Ibrahim Belenli
Keyword(s):  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Electric Conductivity ◽  
Crystal Structures ◽  
Elemental Analysis ◽  
Analysis Data ◽  
Elemental Analysis Data ◽  
The Stability ◽  
Xrd Patterns ◽  
Metal Ligand

Chloro(phenyl)glyoxime, a vicinal dioxime, and its Ni(II), Cu(II) and Co(II) complexes were prepared. XRD patterns of the complexes point to similar crystal structures. IR and elemental analysis data revealed the 1:2 metal-ligand ratio in the complexes. The Co(II) complex is a dihydrate. Temperature dependence of electrical conductivity of the solid ligand and its complexes was measured in the temperature range 25-250 °C; it ranged between 10-14-10-6 Ω-1 cm-1 and increased with rising temperature. The activation energies were between 0.61-0.80 eV. The Co(II) complex has lower electric conductivity than the Ni(II) and Cu(II) complexes. This difference in the conductivity has been attributed to differences in the stability of the complexes.

Structure and Conductivity of Iodine-Doped C60 Thin Films

1994 ◽  
Vol 359 ◽  
Author(s):  
Jun Chen ◽  
Haiyan Zhang ◽  
Baoqiong Chen ◽  
Shaoqi Peng ◽  
Ning Ke ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Thermally Activated ◽  
Order Of Magnitude

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.

Effect of Heat Treatment on Microstructure and Properties of Cu-3Ti-1Al Alloy

2013 ◽  
Vol 749 ◽  
pp. 282-286
Author(s):  
Xian Hui Wang ◽  
Xiao Chun Sun ◽  
Xiao Hong Yang ◽  
Shu Hua Liang
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Electrical Conductivity ◽  
Electron Microscope ◽  
Treatment Process ◽  
Intermetallic Phase ◽  
Strengthening Effect ◽  
Microstructure And Properties ◽  
Optimal Heat Treatment ◽  
Transmission Electron

The effect of heat treatment on the microstructure and properties of Cu-3Ti-1Al alloy was investigated. The microstructure was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), and the hardness and electrical conductivity were tested as well. The results showed that the hardness and electrical conductivity of Cu-3Ti-1Al alloy increased significantly after solid solution and ageing treatment. The strengthening effect of Cu-3Ti-1Al alloy was attributed to the formation of intermetallic phase such as Ti3Al and fine precipitates of coherent β-Cu4Ti. With increase of the aging time and the temperature, the precipitates became coarse and incoherent with Cu matrix, and the discontinuous precipitate β started to grow from grain boundaries toward grain interior, which decreased hardness. As the formation of Ti3Al, β-Cu3Ti and β-Cu4Ti phase can efficiently reduce Ti concentration in Cu matrix. The electrical conductivity of Cu-3Ti-1Al alloy increases. In the range of experiments, the optimal heat treatment process for Cu-3Ti-1Al alloy is solid solution at 850°C for 4h and ageing 500°C for 2h, and the hardness and electrical conductivity are 227HV and 12.3%IACS, respectively.

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