Electrical and thermal properties of Na2SO4 doped with NaVO3, Ln2(SO4)3 (Ln = Eu, Pr)

1983 ◽  
Vol 61 (7) ◽  
pp. 1557-1561 ◽  
Author(s):  
Nobuhito Imanaka ◽  
Gin-Ya Adachi ◽  
Jiro Shiokawa
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Phase Transformation ◽  
Thermal Properties ◽  
Low Temperature ◽  
Apparent Activation Energy ◽  
Solid Electrolytes ◽  
A Value

In order to develop useful solid electrolytes for SO2 detectors, Na2SO4, Na2SO4–Eu2(SO4)3, Na2SO4–NaVO3, and Na2SO4–NaVO3–Ln2(SO4)3 (Ln = Eu, Pr) systems have been prepared, and their electrical and thermal properties have been measured. By doping Na2SO4 with Eu2(SO4)3, the electrical conductivity increases and the apparent activation energy of the Na2SO4–Eu2(SO4)3 system shows a value between those of Na2SO4-III and Na2SO4-I. Addition of NaVO3 and Ln2(SO4)3 (Ln = Eu, Pr) to Na2SO4 suppressed the phase transformation, by stabilizing the structure of the Na2SO4-I phase even at a relatively low temperature.

Influence of B2O3 on Dielectric, Mechanical, and Thermal Properties of MgO-Al2O3-SiO2 Glass-Ceramics

2019 ◽  
Vol 821 ◽  
pp. 435-439
Author(s):  
Bo Li ◽  
Ke Jing ◽  
Hai Bo Bian
Keyword(s):  
Activation Energy ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Low Temperature ◽  
Flexural Strength ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Mechanical And Thermal Properties ◽  
Sintering Process ◽  
Low Thermal Expansion

Low temperature sintered MgO-Al2O3-SiO2 glass-ceramic with high mechanical and low thermal expansion was prepared for package. The remarkable influence of B2O3 addition on the electrical, mechanical, and thermal properties was fully investigated. A small amount of B2O3 promoted the sintering process and improved the densification of MAS. The kinetics via Kissinger method indicated that an appropriate B2O3 content decreased the activation energy and helped the occurrence of crystallization. Due to the increase of crystallinity and indialite phase, B2O3 addition significantly enhanced flexural strength and Young’s modulus. MAS doped with 3wt% B2O3 can be sintered at 900 °C and obtained good properties: σ = 229 MPa, φ = 86 GPa, α = 1.66×10-6 /°C, εr = 5.29, and tanδ = 5.9×10-4.

Apparent Activation Energy in Low Temperature Aging of Y-TZP Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 100-103
Author(s):  
Qi Fei Xie ◽  
Cheng Wang ◽  
Qing Feng Zan ◽  
Li Min Dong
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Apparent Activation Energy ◽  
Coordinate Systems ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Temperature Aging ◽  
Diffraction Patterns ◽  
Straight Lines ◽  
Temperature Aging

Apparent activation energy in low temperature aging of two kinds of Y-TZP ceramic was studied in this paper. The ceramics were processed into small pieces, and aging in 100°C, 110°C, 120°C, 130°C and 140°C respectively. The content of monoclinic phase was calculated by X-ray diffraction patterns and the microstructure was scanned by SEM. According to MAJ law and Arrhenius formation, straight lines were fitted in coordinate systems of ln (ln (1/(1 − f )))-ln t and ln b-1/T, and the kinetic parameters of low temperature aging of Y-TZP ceramic were calculated according to these lines. The results revealed that grain size significantly affected apparent activation energy of Y-TZP ceramics.

Wärmeleitfähigkeit, elektrische Leitfähigkeit, Hall-Effekt, Thermospannung und spezifische Wärme von Ag2Se

1962 ◽  
Vol 17 (10) ◽  
pp. 886-889 ◽  
Author(s):  
Y. Baer ◽  
G. Busch ◽  
C. Fröhlich ◽  
E. Steigmeier
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Low Temperature ◽  
Specific Heat ◽  
Thermoelectric Power ◽  
Hall Coefficient ◽  
A Value ◽  
Price Formula ◽  
Elektrische Leitfähigkeit ◽  
Increasing Temperature

The thermal conductivity, electrical conductivity. Hall coefficient und thermoelectric power of Ag2Se have been measured between 80 and 600°K. In the low temperature semiconductor phase the thermal conductivity increases with increasing temperature due to the high amount of carrier contribution. The latter has been calculated using the Price formula. Agreement with experiment is satisfactory. The specific heat has been measured between 30 and 200°C. For the latent heat a value of (5.7 ± 0.5) cal/gr was determined in agreement with measurements of Bellati and Lussana 4. In addition to the transition at 133 °C an unknown new transition has been found at about 90 °C.

Preparation and Characterization of TeO2 Based Glasses

2005 ◽  
Vol 480-481 ◽  
pp. 315-322 ◽  
Author(s):  
J. Pedlíková ◽  
J. Zavadil ◽  
Olga Prochazková ◽  
J. Kaluzny
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Low Temperature ◽  
Absorption Edge ◽  
Electronic Transitions ◽  
Transmission Range ◽  
Dc Electrical Conductivity ◽  
Pacs Codes ◽  
Low Temperature Photoluminescence

Binary and ternary TeO2 based oxy-chloride glass systems have been prepared and characterised by absorption and low-temperature photoluminescence spectroscopy, and by the measurements of dc electrical conductivity. Prepared glasses exhibit transmittance 75-80% in a broad transmission range 0.3 – 6.5µm with modest shift of upper absorption edge to longer wavelength as heavier ions are introduced into the system. Electronic transitions between 4f-4f inner shells of Pr3+ ions embedded into the host glass have been investigated in a wide temperature range as a function of used precursors used for doping. The temperature dependence of dc electrical conductivity exhibits Arrhenius plots with the single activation energy. PACS codes 81.05.Kf, 78.20.Ci, 78.55.Hx

Electrophysical properties of the (SnSe)1−x–(SmSe)x solid solutions at high and low temperature

2019 ◽  
Vol 34 (01) ◽  
pp. 2050008
Author(s):  
V. A. Abdurahmanova ◽  
N. M. Abdullaev ◽  
Sh. S. Ismayilov
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Low Temperature ◽  
Solid Solutions ◽  
Low Temperatures ◽  
Electrophysical Properties ◽  
Type Specimens ◽  
Text Type ◽  
Donor Type ◽  
Text Density

The temperature range of [Formula: see text] = 77–770 K in the system alloys: Holl coefficient [Formula: see text], thermo-emf [Formula: see text], electric conductivity [Formula: see text], measured [Formula: see text]-density of components and analyzed. It has been established that samarium additive atoms contain donor-type properties and the effectiveness increases with the temperature increase: up to 40% proportional to [Formula: see text] K in [Formula: see text]-type specimens, whereas in [Formula: see text]-type samples this increase is higher and covers the contents of pH varying from [Formula: see text] to [Formula: see text]. An electrical conductivity of compounds increased due to the carrier activation with further increase of temperature. The activation energy of carriers at low temperatures ([Formula: see text] K) is [Formula: see text] eV for [Formula: see text] mol.% and [Formula: see text] mol.% compounds at [Formula: see text] = 77–320 K and for [Formula: see text] mol.% and [Formula: see text] mol.% compounds are [Formula: see text] eV. [Formula: see text] const at [Formula: see text]–400 K for [Formula: see text] mol.% and [Formula: see text] mol.% compounds, and passing with minimum increases at [Formula: see text] = 400–500 K.

Electrical Conductivity and Density of the Molten CaCl2-NaCl-Al2O3 Electrolyte Materials

2010 ◽  
Vol 152-153 ◽  
pp. 19-24
Author(s):  
Hong Wei Xie ◽  
Jin Xia Wang ◽  
Yu Chun Zhai ◽  
Cheng De Li ◽  
Xiao Yun Hu
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Low Temperature ◽  
Arrhenius Equation ◽  
Decisive Factor ◽  
Aluminium Electrolysis ◽  
Cell Constant ◽  
Measurement Temperature ◽  
Temperature Ranges ◽  
Function Relationship

The low-melting CaCl2-NaCl-Al2O3 materials were used as the electrolyte of the low temperature aluminium electrolysis. The electrical conductivity and density of the materials were measured by the Continuously Varying Cell Constant Technique, ac-techniques, and Archimedes method. The materials were composed of 71wt.%~87wt.%CaCl2 (corresponding NaCl), NaCl and Al2O3(without and saturated). The measurement temperature ranges were 550°C~800°C. The results showed that Additive Al2O3 decreased the electrical conductivity of the materials, and resulted in the increase of the activation energy of conductance. The function relationship between the electrical conductivity and temperature was linear, and conformed to the Arrhenius equation. Increasing the CaCl2 content decreased the electrical conductivity of the materials, but the density was increased. With the increase of the CaCl2, the decrease scope of the electrical conductivity was small and the increase trend of the density was slow down. The decisive factor of the electrical conductivity of the materials was temperature.

Low temperature chlorobenzene catalytic oxidation over MnOx/CNTs with the assistance of ozone

RSC Advances ◽  
2015 ◽  
Vol 5 (20) ◽  
pp. 15103-15109 ◽  
Author(s):  
Dongdong Jin ◽  
Zhiyuan Ren ◽  
Zhaoxia Ma ◽  
Fu liu ◽  
Hangsheng Yang
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Apparent Activation Energy ◽  
Catalytic Oxidation ◽  
Complete Oxidation ◽  
P Type

O3 promotes chlorobenzene catalytic oxidation over p-type MnOx/CNTs between 80–240 °C. A CB complete oxidation of 95% is achieved below 120 °C. The reaction follows the L–H mechanism with apparent activation energy of 15.0 kJ mol−1.

Low-temperature electrical conductivity of ternary chalcogenide glasses in the system Se–S

2002 ◽  
Vol 80 (5) ◽  
pp. 599-604 ◽  
Author(s):  
O El-Shazly ◽  
T Ramadan ◽  
M El-Hawary ◽  
N El-Anany ◽  
H A Motaweh ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Low Temperature ◽  
Temperature Region ◽  
Chalcogenide Glasses ◽  
Measured Temperature ◽  
Exponential Factor ◽  
Ternary Chalcogenide ◽  
Extended States ◽  
Made In

Ternary chalcogenide glasses in the system Se–S were prepared by quenching from the melt. Measurements of the temperature dependence of direct current (dc) electrical conductivity have been made in the temperature interval from room temperature down to 30 K. Two types of conduction mechanisms were found to dominate in the measured temperature range, namely band conduction through extended states (which dominates at the high-temperature region) and hopping around the Fermi level (which dominates at the low-temperature region). The dc conductivity activation energy and pre-exponential factor were calculated for the two types of conduction. It was found that the activation energy and the pre-exponential factor are composition dependent. PACS Nos.: 72.20-i, 73.61.Jc, and 81.05.Gc

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