scholarly journals Thermal Expansion of Willemite, Zn2SiO4

1988 ◽  
Vol 41 (6) ◽  
pp. 791 ◽  
Author(s):  
GK White ◽  
RB Roberts
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Linear Thermal Expansion ◽  
Linear Coefficient ◽  
Hexagonal Axis ◽  
Natural Crystal

The linear thermal expansion of a natural crystal of willemite (Zn2Si04) has been measured parallel and normal to the hexagonal axis from 2 to 1200 K. The linear coefficient a" is negative below 150 K and al is negative below room temperature. The Grtineisen parameter 'Y is about 0�5 at 1000 K and falls to less than - 1 below 60 K.

Tangguh LNG Project Statistical Young’s Modulus and Thermal Expansion Coefficient Testing of Clad Pipe Specimens

2011 ◽  
Author(s):  
Terry Griffiths ◽  
Isabel Hadley ◽  
Richard Johnson ◽  
Fabio Micari
Keyword(s):  
Thermal Expansion ◽  
Young’S Modulus ◽  
Room Temperature ◽  
Structural Reliability ◽  
Coefficient Of Thermal Expansion ◽  
Young's Modulus ◽  
Linear Thermal Expansion ◽  
Upheaval Buckling ◽  
Analysis Of Results ◽  
Mean And Variance

Material testing was undertaken on samples taken from clad pipe manufactured by JSW for the Tangguh LNG project. The test programme involved testing Young’s Modulus (E) and Coefficient of Linear Thermal Expansion (α) from room temperature to above 110° on each layer. This paper summarises testing and analysis of results which enabled mean and variance on each material property to be found. Checks were also undertaken for any correlations in properties between clad and parent layers, and between Young’s Modulus and Coefficient of Thermal Expansion. Analysis results are compared to existing industry norms and their implications for the Tangguh project UHB (Upheaval Buckling) SRA (Structural Reliability Analysis) are summarised.

CRYSTAL STRUCTURE, ELECTRICAL CONDUCTIVITY AND THERMAL EXPANSION OF Pr1-xSrxFeO3-δ(0 ≤ x ≤ 0.6)

2012 ◽  
Vol 26 (32) ◽  
pp. 1250174 ◽  
Author(s):  
V. PRASHANTH KUMAR ◽  
Y. S. REDDY ◽  
P. KISTAIAH ◽  
C. VISHNUVARDHAN REDDY
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Room Temperature ◽  
Small Polaron ◽  
Linear Thermal Expansion ◽  
Lattice Parameter ◽  
Polaron Hopping ◽  
X Ray ◽  
Perovskite Type

The crystal structure at room temperature (RT), thermal expansion from RT to 1000°C and electrical conductivity, from RT to 600°C, of the perovskite-type oxides in the system Pr 1-x Sr x FeO 3(x = 0, 0.2, 0.4, 0.6) were studied. All the compounds have the orthorhombic perovskite GdFeO 3-type structure with space group Pbnm. The lattice parameters were determined by X-ray powder diffraction. The Pseudo cubic lattice parameter decreases with an increase in x, while the coefficient of linear thermal expansion increases. The thermal expansion is almost linear for x = 0 and 0.2. The electrical conductivity increases with increasing x while the activation energy decreases. The electrical conductivity can be described by the small polaron hopping conductivity model.

Confirmation of the new technique for measuring the linear thermal expansion of silicon

1993 ◽  
Vol 8 (1) ◽  
pp. 36-38 ◽  
Author(s):  
Liu Fengchao
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Accurate Determination ◽  
Linear Thermal Expansion ◽  
Linear Expansion Coefficient ◽  
X Ray ◽  
High Purity Silicon ◽  
Different Temperatures ◽  
Better Than

This paper further confirms that the direct measurement of diffraction angles at different temperatures by using the X-ray diffractometer is better than measurement of the lattice parameters for the rapid and accurate determination of the linear thermal expansion of silicon. High purity silicon has the linear expansion coefficient, α= (2.45±0.05) × 10−6/°C at room temperature. This value does not change for doped P-type and N-type silicon.

Controllable Thermal Expansion in In2-xFexMoxO12

2014 ◽  
Vol 602-603 ◽  
pp. 677-680
Author(s):  
Mei Mei Wu ◽  
Yun Tao Liu
Keyword(s):  
Thermal Expansion ◽  
Solid Solutions ◽  
Room Temperature ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Orthorhombic Phase ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fe Content

The structural and thermal expansion properties of solid solutions In2-xFexMo3O12have been characterized using X-ray diffraction. The lattice parameters decrease linearly with increasing Fe content at room temperature. All compounds exhibit monoclinic structure at room temperature, and transform to orthorhombic phase upon heating. Monoclinic In2-xFexMo3O12(x= 0.3, 1.0 and 1.3) possess strong positive thermal expansion, while the linear thermal expansion coefficient of orthorhombic phase varies from zero/near-zero to positive with increasing Fe3+content.

The Linear Coefficient of Thermal Expansion of Silicon at Room Temperature

1991 ◽  
Vol 6 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Liu Fengchao ◽  
Zheng Bin
Keyword(s):  
Thermal Expansion ◽  
Single Crystal ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Silicon Single Crystal ◽  
Linear Coefficient ◽  
X Ray ◽  
Crystal State ◽  
Powder Diffractometer ◽  
Powder Samples

AbstractThe linear coefficient of thermal expansion for three silicon single-crystal samples, taken from the head, middle, and tail of the same boule, and their powder samples have been measured at room temperature by using an X-ray powder diffractometer. All samples yield the same expansion value α=2.45 (± 0.04) × 10−6 °C at 25 °C. The results of this experiment show that the linear coefficient of thermal expansion of silicon at room temperature is not dependent on its single-crystal state or its powder state.

Structure, crystal growth and physical anisotropy of KYb(WO4)2, a new laser matrix

2002 ◽  
Vol 35 (1) ◽  
pp. 108-112 ◽  
Author(s):  
M. C. Pujol ◽  
X. Mateos ◽  
R. Solé ◽  
J. Massons ◽  
Jna. Gavaldà ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Principal Axis ◽  
Linear Thermal Expansion ◽  
X Ray Diffraction ◽  
Slow Cooling ◽  
Thermal Expansion Tensor ◽  
Principal Axes ◽  
Top Seeded Solution Growth ◽  
Prime 2

The crystal structure of monoclinic KYb(WO4)2(KYbW) crystals has been refined (in space groupC2/c) at room temperature by using single-crystal X-ray diffraction data. KYbW undoped crystals were grown by the TSSG (top-seeded-solution growth) slow-cooling method. The crystals show {110}, {\bar{1}11}, {010} and {310} faces, which basically define their habit. The linear thermal expansion tensor has been determined and the principal axis with maximum thermal expansion (\alpha ^{\,\prime}_{33} = 16.68 × 10−6 K−1), {\bf X}^{\,\prime}_{3}, was located 12° from thecaxis. Its principal {\bf X}^{\,\prime}_{1}, {\bf X}^{\,\prime}_{2} and {\bf X}^{\,\prime}_{3} axes are [302], [010] and [106] directions, respectively, in the crystallographic system. The optical tensor has been studied at λ = 632.8 nm at room temperature; two principal axes,NgandNm, are located in theacplane, while the other,Np, is parallel to [010]. The principal axis with maximum refractive index (ng= 2.45),Ng, was located 19° from thecaxis.

Phosphorescence of Manganese(II) in Single Crystals of [Mn(CO(NH2)2)6](ClO4)2

1978 ◽  
Vol 33 (3) ◽  
pp. 377-379 ◽  
Author(s):  
E. Koglin ◽  
H. J. Schenk
Keyword(s):  
Thermal Expansion ◽  
Single Crystals ◽  
Thermal Expansion Coefficient ◽  
Crystal Field ◽  
Room Temperature ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Phosphorescence Spectrum ◽  
Excitation Spectra ◽  
Crystal Field Parameters

AbstractThe 4T1g(t42g e1g) → 6A1g(t32g e2g) phosphorescence spectrum of manganese (II) in single crystals of[Mn(CO(NH2)2)6] (ClO4)2has been recorded in the temperature range of 4.2 to 298 K. With decreasing temperature the emission maximum is shifted from 17138 cm-1 (298 K) to 16809 cm-1 (4.2 K). This red shift points to a linear thermal expansion coefficient of α = 24 · 10-6 K-1. Crystal field parameters of Dq = 748 cm-1 and B = 827cm-1 have been calculated from the room temperature absorption and excitation spectra.

scholarly journals The Structure, Vibrational Spectra, and Thermal Expansion Study of AVO4 (A=Bi, Fe, Cr) and Co2V2O7

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1628 ◽  
Author(s):  
Xiaoke He ◽  
Chenjun Zhang ◽  
Ding Tian
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Monoclinic Structure ◽  
Functional Material ◽  
Temperature Dependent ◽  
Vanadium Compounds ◽  
Measurement Results ◽  
Thermal Expansion Study

Vanadate is an important functional material. It has been widely studied and applied in luminescence and photocatalysis. Vanadium compounds have been synthesized to investigate the thermal expansion properties and structure. Both BiVO4 and Co2V2O7 are monoclinic at room temperature, FeVO4’s crystal structure is triclinic, and CrVO4 is orthorhombic. The relatively linear, thermal-expansion, and temperature-dependent Raman spectroscopy results showed that the phase transition of BiVO4 occurred at 200 to 300 °C. The coefficient of thermal expansion (CTE) of Co2V2O7 was larger than that of the monoclinic structure BiVO4. The CTE of the tetragonal structure of BiVO4 was 15.27 × 10−6 °C−1 which was the largest CTE in our measurement results, and the CTE of anorthic structure FeVO4 was 2.84 × 10−6 °C−1 and was the smallest.

Nonlinear thermal expansion in Li2NiMn3O8

2008 ◽  
Vol 23 (3) ◽  
pp. 224-227
Author(s):  
Lingmin Zeng ◽  
Yeqing Chen ◽  
Wei He ◽  
Liangqin Nong
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Room Temperature ◽  
Linear Thermal Expansion ◽  
Lithium Ion ◽  
Entire Temperature Range ◽  
X Ray Diffraction ◽  
Spinel Type ◽  
X Ray ◽  
Temperature Range

A lattice thermal expansion study on Li2NiMn3O8, a high-voltage cathode material for lithium-ion batteries, was carried out by high-temperature X-ray diffraction from room temperature to 973 K. Rietveld refinement of a high-quality room-temperature diffraction pattern confirmed that Li2NiMn3O8 has the cubic Al2MgO4 spinel type of crystal structure. The analysis of the high-temperature X-ray diffraction patterns showed that the Li2NiMn3O8 structure remained stable and no phase transition was detected over the temperature range from 298 to 973 K. As expected, the value of lattice parameter a or unit cell volume V increases with increasing temperature. The increase in a or V is linear only in the low-temperature region and nonlinear over the entire temperature range from 298 to 973 K. Least-squares analysis of the data for a or V showed the thermal expansion of a or V for Li2NiMn3O8 can best be fitted by a 3-degree polynomial function of temperature. The linear thermal expansion coefficients for a and V averaged over the entire temperature range from 298 to 973 K were also calculated, and αTa=1.10×10−5 K−1; αTV=3.29×10−5 K−1.

Structural redetermination, thermal expansion and refractive indices of KLu(WO4)2

2006 ◽  
Vol 39 (2) ◽  
pp. 230-236 ◽  
Author(s):  
M. C. Pujol ◽  
X. Mateos ◽  
A. Aznar ◽  
X. Solans ◽  
S. Suriñach ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Near Infrared ◽  
Linear Thermal Expansion ◽  
Unit Cell ◽  
Visible Range ◽  
Unit Cell Parameters ◽  
Slow Cooling ◽  
Cell Parameters ◽  
Thermal Expansion Tensor

The crystal structure of monoclinic KLu(WO4)2(KLuW) crystals was determined at room temperature by using single-crystal X-ray diffraction data. The unit-cell parameters werea= 10.576 (7),b= 10.214 (7),c= 7.487 (2) Å, β = 130.68 (4)°, withZ= 4, in space groupC2/c. The unit-cell parameters of KLu1−xYbx(WO4)2were determined in relation to Yb concentration. Vickers micro-indentations were used to study the microhardness of KLuW. The linear thermal expansion tensor was determined and the principal axis with maximum thermal expansion (\alpha_{33}' = 16.72 × 10−6 K−1), X_3', was located 13.51° from thecaxis. The room-temperature optical tensor was studied in the near-infrared (NIR) and visible range. The principal optical axis with maximum refractive index (ng= 2.113),Ng, was located 18.5° from thecaxis at 632.8 nm. Undoped and ytterbium-doped KLuW crystals were grown by the TSSG (top-seeded-solution growth) slow-cooling method. The crystals show {110}, {\bar{1}11}, {010} and {310} faces that basically constitue the habit of the KLuW crystals.

Sign in / Sign up

Export Citation Format

Share Document