scholarly journals The thermal expansion of bismuth by X-ray measurements

1934 ◽  
Vol 143 (849) ◽  
pp. 465-472 ◽  
Keyword(s):  
Thermal Expansion ◽  
Melting Point ◽  
Single Crystals ◽  
Room Temperature ◽  
The Other ◽  
Optical Methods ◽  
Lattice Expansion ◽  
X Ray ◽  
Expansion Curve ◽  
Methods Of Measurement

X-ray measurements recently carried out by the author on the lattice expansion of silver and quartz showed that the coefficients of thermal expansion, over the ranges investigated, are the same as those observed for the specimen as a whole using optical methods. Goetz and Hergenrother, on the other hand, from X-ray measurements on the coefficients of thermal expansion of single crystals of bismuth, claimed to have found a large difference between values obtained by the two methods of measurement. A possible explanatiion of this that their accuracy is not sufficient to establish definitely the deviation of the X-ray measurements from the optical expansion curve. The author has since made X-ray measurements on the expansion of the bismuth lattice from room temperature to just below the melting point, and finds no evidence of such a discrepancy as Goetz and Hergenrother record.

The thermal expansion and high temperature transformation of SnS and SnSe*

1979 ◽  
Vol 149 (1-2) ◽  
Author(s):  
Heribert Wiedemeier ◽  
Frank J. Csillag
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Melting Point ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Square Planar ◽  
Orthorhombic Modification ◽  
Temperature Transformation ◽  
Increasing Temperature

AbstractThe thermal expansion of SnS and SnSe has been studied above room temperature up to the melting point of 1163 ± 5K and 1135 ± 5K, respectively, by X-ray diffraction techniques using a 190 mm Unicam high temperature camera. The changes of the lattice parameters indicate that the atomic positions in the (010) plane approach a square planar arrangement with increasing temperature. The transformation of SnS and SnSe from orthorhombic to a pseudotetragonal orthorhombic modification with

Crystal structure, dielectric, piezoelectric and elastic properties of (±)-tris(ethylenediamine)cobalt(III) nitrate, (±)–[Co(H2N(CH2)2NH2)3](NO3)3

1998 ◽  
Vol 213 (3) ◽  
Author(s):  
S. Haussühl ◽  
J. Schreuer
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Single Crystals ◽  
Elastic Properties ◽  
Structure Analysis ◽  
Elastic Constants ◽  
Room Temperature ◽  
Optical Quality ◽  
X Ray

AbstractLarge single crystals of optical quality of (±)-tris(ethylenediamine)cobalt(III) nitrate have been grown from aequeous solutions. An X-ray structure analysis yielded space groupPyroelectric, dieletric, piezoelectric and elastic constants have been determined at room temperature. Additionally, we have studied the coefficients of thermal expansion and the thermoelastic constants in the range between 270 K and 350 K. The structure exhibits a nearly trigonal symmetry around the [unk]

Phase Transition and Thermal Expansion of Ba3RB3O9 (R = Sm–Yb, and Y)

2017 ◽  
Vol 36 (8) ◽  
pp. 763-769 ◽  
Author(s):  
Rayko Simura ◽  
Shohei Kawai ◽  
Kazumasa Sugiyama
Keyword(s):  
Phase Transition ◽  
Thermal Expansion ◽  
High Temperature ◽  
Thermal Expansion Coefficient ◽  
Room Temperature ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Melting Temperatures ◽  
Type Phase

AbstractHigh temperature powder X-ray diffraction measurements of Ba3RB3O9 (R=Sm–Yb, and Y) were carried out at temperatures ranging from room temperature to just below the corresponding melting temperatures (1,200–1,300 °C). No phase transition was found for the H-type phase (R$\overline 3 $) with R=Sm–Tb and the L-type phase (P63 cm) with R=Tm–Yb. On the other hand, phase transition from the L phase to the H phase was observed for R=Dy–Er, and Y at around 1,100–1,200 °C. The obtained axial thermal expansion coefficient (ATEC) of the a-axis was larger than that of the c-axis for the H phase, and the ATEC of the c-axis was larger than that of the a-axis for the L phase. The observed anisotropic nature of ATEC is attributed to the distribution of the BO3 anionic group with rigid boron–oxygen bonding in the structures of the H and L phases.

Effect of trytophan as dopant on potassium acid phthalate single crystals

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Evaporation Technique ◽  
Potassium Acid Phthalate ◽  
Acid Phthalate

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.

The Characteristic of the La3Ga5SiO14 Single Crystal Grown by Vertical Bridgman Method in Ar Atmosphere

2006 ◽  
Vol 510-511 ◽  
pp. 842-845 ◽  
Author(s):  
Noriko Bamba ◽  
Kentaro Kato ◽  
Toshinori Taishi ◽  
Takayuki Hayashi ◽  
Keigo Hoshikawa ◽  
...  
Keyword(s):  
Melting Point ◽  
Single Crystal ◽  
Single Crystals ◽  
Room Temperature ◽  
Color Change ◽  
Piezoelectric Materials ◽  
Lead Free ◽  
Piezoelectric Constant ◽  
Interstitial Oxygen ◽  
Vertical Bridgman

Langasite (La3Ga5SiO14: denoted by LGS) single crystal is one of the lead free piezoelectric materials with high piezoelectricity that is maintained up to its melting point (1470°C). Although LGS single crystals have usually been grown by Czochralski (CZ) method in oxygen contained atmosphere to prevent evaporation of Ga, they were grown by the vertical Bridgman (VB) method in Ar atmosphere without oxygen, and their properties were evaluated in this work. Transparent and colorless LGS single crystals were successfully obtained without Ga evaporation by the VB method in Ar atmosphere, and their resistivity at room temperature was much higher than that grown by conventional CZ method. Piezoelectric constant d11 of the crystal grown by the VB method was 6 x 10-12 C/N, which was close to that of the crystal grown by CZ method. The colorless transparent LGS single crystal turned to orange and its resistivity decreased by annealing in air. Since an orange-colored transparent LGS single crystal has been grown by conventional CZ method, this indicates that color change and the resistivity decrease of LGS crystal is caused by extra interstitial oxygen atoms in the crystal.

Generation of Defects and Strain by Ion Implantation in Ge (100) Single Crystals, and in Pseudomorphic GexSi1-x Films Grown on Si (100)

1992 ◽  
Vol 262 ◽  
Author(s):  
D. Y. C. Lie ◽  
A. Vantomme ◽  
F. Eisen ◽  
M. -A. Nicolet ◽  
V. Arbet-Engels ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystals ◽  
Room Temperature ◽  
Defect Concentration ◽  
Double Crystal ◽  
X Ray ◽  
Positive Strain ◽  
Independent Coefficient ◽  
The Relationship ◽  
Si Ion Implantation

ABSTRACTWe have studied the damage and strain produced in Ge (100) single crystals by implantation of various doses of 300 keV 28Si ions at room temperature. The analyzing tools were x-ray double-crystal diffractometry, and MeV 4He channeling spectrometry. The damage induced by implantation produces positive strain in Ge (100). The maximum perpendicular strain and maximum defect concentration rise nonlinearly with increasing dose. These quantities are linearly related with a dose-independent coefficient of ∼ 0.013 for Ge (100) single crystals implanted at room temperature. The results are compared with those available for Si (100) self-implantation. We have also monitored the strain and defects generated in pseudomorphic Ge0.1Si0.9/Si (100) films induced by room temperature 28Si ion implantation. It is found that the relationship between the strain and defect concentration induced by ion implantation is no longer a simple linear one.

Study on Schottky Diode Characteristics Improving by X-Ray Irradiation

2013 ◽  
Vol 717 ◽  
pp. 113-116
Author(s):  
Sani Klinsanit ◽  
Itsara Srithanachai ◽  
Surada Ueamanapong ◽  
Sunya Khunkhao ◽  
Budsara Nararug ◽  
...  
Keyword(s):  
Leakage Current ◽  
Schottky Diode ◽  
Room Temperature ◽  
The Other ◽  
Low Power Consumption ◽  
Initial Value ◽  
X Ray ◽  
Forward Current ◽  
Current Voltage ◽  
Current Voltage Characteristics

The effect of soft X-ray irradiation to the Schottky diode properties was analyzed in this paper. The built-in voltage, leakage current, and work function of Schottky diode were investigated. The current-voltage characteristics of the Schottky diode are measured at room temperature. After irradiation at 70 keV for 55 seconds the forward current and leakage current are increase slightly. On the other hand, the built-in voltage is decrease from the initial value about 0.12 V. Consequently, this method can cause the Schottky diode has low power consumption. The results show that soft X-ray can improve the characteristics of Schottky diode.

Phase Transitions in Hoalga

1983 ◽  
Vol 21 ◽  
Author(s):  
M. Doukoure ◽  
D. Gignoux ◽  
F. Sayetat
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Magnetic Order ◽  
Magnetocrystalline Anisotropy ◽  
Exchange Interactions ◽  
Thermal Anomaly ◽  
Antiferromagnetic State ◽  
Hexagonal Symmetry ◽  
X Ray ◽  
Magnetic Structures

ABSTRACTHoAlGa is hexagonal at room temperature. It undergoes two magnetic transitions succesively at TN = 32 K from a paramagnetic to a triangular antiferromagnetic state where the Ho moments lie in the basal plane and at Tt = 18 K in the course of which the moments rotate toward c giving rise to a colinear antiferromagnetic arrangement. X-ray experiments performed between 5 and 300 K allow to determine the crystal evolution through the two transitions. The hexagonal symmetry is not lowered through the transitions; this result is compatible with the observed magnetic groups. The thermal expansion curves show a very anisotropic behaviour of the lattice parameters. The “c” parameter shrinks below TN and this anomaly is to be related to the magnetic order. Along a, a positive thermal anomaly appears below 70 K and this can be interpreted by crystal field effects. Stability of magnetic structures is discussed with regard to exchange interactions and magnetocrystalline anisotropy.

Enhanced Piezoelectric Properties of Piezoelectric Single Crystals by Domain Engineering

2003 ◽  
Vol 785 ◽  
Author(s):  
Satoshi Wada ◽  
Koichi Yako ◽  
Hirofumi Kakemoto ◽  
Takaaki Tsurumi
Keyword(s):  
Single Crystals ◽  
Domain Structure ◽  
Room Temperature ◽  
Piezoelectric Properties ◽  
Domain Size ◽  
Domain Engineering ◽  
The Other ◽  
Domain Structures ◽  
Domain Configuration ◽  
Fine Domain

ABSTRACTFor tetragonal barium titanate (BaTiO3) single crystals, an electric field (E-field) applied along [111]c direction can induce an engineered domain configuration. In this study, the engineered domain structures with different domain sizes were induced into BaTiO3 single crystals, and their piezoelectric properties were investigated as a function of a domain size. Prior to this study, the dependence of domain configuration on the temperature and the E-field was investigated using a polarizing microscope in order to understand the optimum condition for fine and coarse domain structures. As a result, above Curie temperature (Tc) of 132.2 °C, when the E-field over 6 kV/cm was applied along [111]c direction, the engineered domain configuration with fine domain structure appeared. Moreover, it was also found that this fine domain structure was still stable at room temperature without E-field. On the other hand, the coarse domain structure was obtained by poling at just below Tc. Finally, the piezoelectric properties were measured using the 31 resonators with different kinds of domain sizes. As the result, it was found that the piezoelectric properties such as d31 and k31 increased significantly with decreasing domain sizes.

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