THERMAL EXPANSION, GRUENEISEN PARAMETER, AND TEMPERATURE DEPENDENCE OF LATTICE VIBRATION FREQUENCIES OF ALUMINUM OXIDE

1965 ◽  
Vol 43 (4) ◽  
pp. 523-531 ◽  
Author(s):  
Alois Schauer
Keyword(s):  
Thermal Expansion ◽  
Aluminum Oxide ◽  
Temperature Dependence ◽  
Lattice Vibration ◽  
Linear Thermal Expansion ◽  
Vibration Frequencies ◽  
Polycrystalline Aluminum ◽  
Interferometric Method ◽  
Temperature Range ◽  
Wide Range

The linear thermal expansion coefficient of polycrystalline aluminum oxide has been measured in the temperature range from 100 °K to 1 500 °K by an interferometric method. The interferometer used is capable of giving high accuracy over a wide range of temperatures, and is described in some detail. The Grueneisen parameter of aluminum oxide is calculated and found to be 1.35 ± 0.05 over the whole temperature range. There is no significant change, such as might be expected from theory, of the Grueneisen parameter around 0.2 × Debye temperature. Based on the formulae given in an earlier publication, the temperature dependence of lattice vibration frequencies of aluminum oxide is calculated.

scholarly journals Studies on Thermophysical Properties of CaO and MgO by γ-Ray Attenuation

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
A. S. Madhusudhan Rao ◽  
K. Narender
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Thermophysical Properties ◽  
Linear Thermal Expansion ◽  
Temperature Dependent ◽  
Degree Polynomial ◽  
Attenuation Coefficients ◽  
Temperature Range ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

The study on temperature dependent γ-ray attenuation and thermophysical properties of CaO and MgO has been carried out in the temperature range 300 K–1250 K using different energies of γ-beam, namely, Am (0.0595 MeV), Cs (0.66 MeV), and Co (1.173 MeV and 1.332 MeV) on γ-ray densitometer fabricated in our laboratory. The linear attenuation coefficients (μl) for the pellets of CaO and MgO as a function of temperature have been determined using γ-beam of different energies. The coefficients of temperature dependence of density have been reported. The variation of density and linear thermal expansion of CaO and MgO in the temperature range of 300 K–1250 K has been studied and compared with the results available in the literature. The temperature dependence of linear attenuation coefficients, density, and thermal expansion has been represented by second degree polynomial. Volume thermal expansion coefficients have been reported.

THERMAL EXPANSION OF SOLIDS AND THE TEMPERATURE DEPENDENCE OF LATTICE VIBRATION FREQUENCIES

1964 ◽  
Vol 42 (10) ◽  
pp. 1857-1864 ◽  
Author(s):  
Alois Schauer
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Lattice Vibration ◽  
Close Relation ◽  
Vibration Frequencies ◽  
Temperature Ranges ◽  
Basic Equations ◽  
Volume Thermal Expansion Coefficient

It is shown that a close relation exists between the temperature coefficient of lattice vibration frequencies and the thermal expansion coefficient. The basic equations[Formula: see text](νi being the frequency of the ith mode of vibration, T the temperature, Ci the Einstein function of frequency νi, γ the Grueneisen parameter, and β the volume thermal expansion coefficient) are derived and discussed for various temperature ranges.

scholarly journals Thermal Expansion and Electro-Elastic Features of Ba2TiSi2O8 High Temperature Piezoelectric Crystal

Crystals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 11 ◽  
Author(s):  
Chao Jiang ◽  
Feifei Chen ◽  
Fapeng Yu ◽  
Shiwei Tian ◽  
Xiufeng Cheng ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Elastic Properties ◽  
Piezoelectric Coefficient ◽  
Linear Thermal Expansion ◽  
Temperature Stability ◽  
Promising Candidate ◽  
Temperature Range ◽  
Sensor Applications ◽  
High Temperature Sensor

A high-quality Ba2TiSi2O8 (BTS) single crystal was grown using the Czochralski (Cz) pulling method. The thermal expansion and electro-elastic properties of BTS crystal were studied for high temperature sensor applications. The relative dielectric permittivities ε 11 T / ε 0 and ε 33 T / ε 0 were determined to be 16.3 and 11.8, while the piezoelectric coefficients d15, d31, d33 were found to be 17.8, 2.9, and 4.0 pC/N, respectively. Temperature dependence of electro-elastic properties were investigated, where the variation of elastic compliance s 55 E (= s 44 E ) was found to be <6% over temperature range of 20–700 °C. Taking advantage of the anisotropic thermal expansion, linear thermal expansion comparable to insulating alumina ceramic was achieved over temperature range up to 650 °C. The optimum crystal cut with large effective piezoelectric coefficient (>8.5 pC/N) and linear thermal expansion coefficient (8.03 ppm/°C) achieved for BTS crystal along the (47°, φ) direction (φ is arbitrary in 0–360°), together with its good temperature stability up to 650 °C, make BTS crystal a promising candidate for high temperature piezoelectric sensors.

Linear Thermal Expansion of Lead-Free Piezoelectric K0.5Na0.5NbO3 Ceramics in a Wide Temperature Range

2011 ◽  
Vol 94 (8) ◽  
pp. 2273-2275 ◽  
Author(s):  
Barbara Malič ◽  
Helena Razpotnik ◽  
Jurij Koruza ◽  
Samo Kokalj ◽  
Jena Cilenšek ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Wide Temperature Range ◽  
Linear Thermal Expansion ◽  
Lead Free ◽  
Temperature Range

Combustion Synthesis of ZrW2O8 and Preparation of its Composite with Near Zero Thermal Expansion

2007 ◽  
Vol 353-358 ◽  
pp. 1235-1238 ◽  
Author(s):  
Xue Yan ◽  
Xiao Nong Cheng ◽  
Xin Bo Yang ◽  
Cheng Hua Zhang
Keyword(s):  
Thermal Expansion ◽  
Combustion Synthesis ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Weight Ratio ◽  
Combustion Method ◽  
Temperature Range ◽  
Thermal Expansion Property

ZrW2O8 was successfully synthesized via combustion method with (NH4)5H5[H2(WO4)6] ·H2O, ZrOCl2·8H2O, H3BO3, (NH2)2CO and HNO3. The best prescription of combustion synthesizing of ZrW2O8 was obtained. The linear thermal expansion coefficient of synthesized ZrW2O8 is -5.08×10-6oC-1 in the temperature range of 50-600oC. Different weight ratios of ZrW2O8 and ZrO2 were taken into account. Al2O3 was added into the composite during sintering to increase the density of the composites. When the weight ratio of ZrO2 to ZrW2O8 is 2, the composite with near zero thermal expansion can be obtained. 0.25 wt% Al2O3 can effectively increase the density of ZrO2/ZrW2O8 composites with slight influence on the thermal expansion property.

THERMO-MECHANICAL ANALYSIS OF HETEROGENEOUS SOLID ROCKET PROPELLANT

2019 ◽  
Vol 147 (3/2018) ◽  
pp. 105-121
Author(s):  
Marcin Cegla ◽  
Janusz Zmywaczyk ◽  
Piotr Koniorczyk
Keyword(s):  
Thermal Expansion ◽  
Loss Modulus ◽  
Linear Thermal Expansion ◽  
Softening Temperature ◽  
Mechanical Analysis ◽  
Solid Rocket Propellant ◽  
Rocket Propellant ◽  
Temperature Range ◽  
Solid Rocket ◽  
Heterogeneous Solid

The article presents results of thermo-mechanical analysis of heterogeneous solid rocket propellant H2, with special attention devoted to determining the glass transition temperature and softening temperature. Mechanical properties such as storage modulus (E’), loss modulus (E’’) and tan(δ) were measured using NETZSCH DMA 242C analyzer within temperature range from -120oC to +80oC at 2 K/min of heating rate and frequency of applied force f = 1 Hz. Relative thermal expansion as well as the Coefficient of Linear Thermal Expansion (CLTE) of H2 sample were determined using NETZSCH DIL 402C dilatometer within temperature range from 30oC to 80oC at 1 K/min of heating/cooling rate. The thermophysical properties including thermal conductivity, thermal diffusivity, and specific heat were determined within temperature range from -20oC to +80oC using KD2 Pro apparatus.

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