Growth and Characterization of Series Nd:GdxLa1-xVO4 (x = 0.80, 0.60, 0.45) Crystals

2002 ◽  
Vol 17 (3) ◽  
pp. 556-562 ◽  
Author(s):  
Huaijin Zhang ◽  
Changqing Wang ◽  
Li Zhu ◽  
Xuesong Liu ◽  
Guanghui Zhang ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Specific Heat ◽  
Laser Diode ◽  
Room Temperature ◽  
Emission Spectra ◽  
Czochralski Method ◽  
Crystal Sample ◽  
Lattice Constants ◽  
Intracavity Frequency

In this paper, series crystals Nd:Gd0.8La0.2VO4, Nd:Gd0.6La0.4VO4, and Nd:Gd0.45La0.55VO4 were grown by the Czochralski method. The structure and lattice constants of the series crystals were measured. The morphology of Nd:Gd0.8La0.2VO4 is discussed, and it is composed of {100} and {101} simple forms. The thermal expansion and specific heat of the Nd:Gd0.8La0.2VO4 crystal were also measured. The absorption and emission spectra of the Nd:Gd0.8La0.2VO4 and Nd:Gd0.6La0.4VO4 crystals were measured at room temperature. The laser outputs at 1.06 and 1.34 μm were determined when a crystal sample of Nd:Gd0.8La0.2VO4 was pumped by a laser diode at 808 nm, and the visible green and red laser outputs of the intracavity frequency double at 0.53 and 0.67 μm were determined when nonlinear KTiOPO4 and LiB3O5 crystals were used.

Crystal Distortion Associated with Magnetic Ordering in Alpha Iron Oxide and Manganese Carbonate

1972 ◽  
Vol 16 ◽  
pp. 390-395 ◽  
Author(s):  
W. S. McCain ◽  
D. L. Albright
Keyword(s):  
Thermal Expansion ◽  
Lattice Constant ◽  
Room Temperature ◽  
Axial Ratio ◽  
Manganese Carbonate ◽  
Lattice Constants ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Position Parameter ◽  
Oxygen Distance

AbstractThe magnetic crystal disrortion of weakly ferromagnetic α-Fe2O3 was investigated by x-ray diffraction techniques. Here crystal distortion is taken as the temperature dependent changes of lattice constants and thermal expansion coefficients. Moreover, the oxygen position parameter and the carbon-oxygen distance of MnCO3 were determined.The lattice constants and thermal expansion coefficients of α-Fe2O3 were measured from room temperature down to 243°K. The crystal distortion, as measured by the changes in lattice constants, thermal expansion coefficients and axial ratio, was found to be highly anisotropic. The co hexagonal lattice constant was influenced very slightly by magnetic distortion; it changed only by 0.01 percent between room temperature and the Morin temperature of 254°K. On the other hand, the ao lattice constant changes by 0.11 percent between room temperature and the Morin temperature. The thermal expansion coefficients of the lattice constants showed a similar contrast. The co coefficient was found to be independent of temperature from room temperature down to the Morin temperature. However, in the same temperature range, the ao coefficient showed an anomalous increase with decreasing temperature. In addition, the ao coefficient showed an infinite discontinuity at the Morin temperature.The change in the axial ratio with temperature suggests that the net weak ferromagnetic moment of α-Fe2O3 reaches a maximum at 275°K.The oxygen position parameter, x, in MnCO3 as determined from two reflections has a value of 0.2702 ± 0.001. The carbon-oxygen distance as calculated from the lattice constants and the oxygen position parameter is 1.29 ±0.002 Å. This value is another confirmation of the Pauling theory of the resonating carbonate structure.

Synthesis and structural characterization of BaV4O9

2007 ◽  
Vol 63 (2) ◽  
pp. 270-276 ◽  
Author(s):  
Thomas Reeswinkel ◽  
Sebastian Prinz ◽  
Karine M. Sparta ◽  
Georg Roth
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Structural Characterization ◽  
Room Temperature ◽  
Monoclinic Space Group ◽  
Temperature Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Tensor

The new spin ½ V4+ barium oxovanadate BaV4O9 was synthesized and studied by means of single-crystal X-ray diffraction. Its room-temperature structure is monoclinic, space group P2/c. We discuss the temperature evolution of the crystal structure and thermal expansion tensor of the material between 293 and 100 K.

scholarly journals Synthesis, X-Ray Structure, and Characterization of a Complex Containing the Hexakis(urea)cobalt(II) Cation and Lattice Urea Molecules

2007 ◽  
Vol 2007 ◽  
pp. 1-7 ◽  
Author(s):  
Labrini Drakopoulou ◽  
Constantina Papatriantafyllopoulou ◽  
Aris Terzis ◽  
Spyros P. Perlepes ◽  
Evy Manessi-Zoupa ◽  
...  
Keyword(s):  
Room Temperature ◽  
Three Dimensional ◽  
Monoclinic Space Group ◽  
Two Dimensional ◽  
X Ray ◽  
Lattice Constants ◽  
Dimensional Network ◽  
Different Types ◽  
Hydrogen Bonded

The 12: 1 reaction of urea (U) with CoI2in EtOH yielded the “clathrate-coordination” compound[CoU6]I2·4U (1). The complex crystallizes in the monoclinic space group P21/c. The lattice constants area= 9.844(4),b= 7.268(3),c= 24.12(1) Å, andβ=98.12(1)∘. The crystal structure determination demonstrates the existence of octahedral[CoU6]2+cations,I-counterions, and two different types (twoU1and twoU2) of hydrogen-bonded, lattice urea molecules. The[CoU6]2+cations and theU1lattice molecules form two-dimensional hydrogen-bonded layers which are parallel to theabplane. TheI-anions are placed above and below each layer, and are hydrogen bonded both toU1molecules and[CoU6]2+cations. EachU2molecule is connected to a[CoU6]2+cation through anN–H⋯Ohydrogen bond resulting in a three-dimensional network. Room temperature magnetic susceptibility and spectroscopic (solid-state UV/Vis, IR, Raman) data of1are discussed in terms of the nature of bonding and the known structure.

Thermal Expansion of Oxyarsenides (LaO)TAs; T = Transition Metal

2011 ◽  
Vol 170 ◽  
pp. 131-134 ◽  
Author(s):  
Shintaro Otsuka ◽  
Manami Onizawa ◽  
Koma Kato ◽  
Shozo Hiramoto ◽  
Fumiko Yoshida ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Room Temperature ◽  
High Energy ◽  
Parent Material ◽  
X Ray ◽  
Lattice Constants ◽  
Temperature Dependences ◽  
Temperature Lattice ◽  
Diffraction Lattice

We have investigated the precise crystal structure and their temperature dependences of oxyarsenides (LaO)TAs; T = Mn, Fe, Co, as the Fe based superconductor’s parent material family using high energy synchrotron radiation x-ray powder diffraction. Lattice constants a and c decrease with decreasing temperature. Focusing the ratios of the changes normalized by room temperature lattice constants, we have found anisotropic shrinks for the superconductor’s parent material of (LaO)FeAs and the ferromagnetic metal (LaO)CoAs. The shrinkage of the lattice constant c along the stacking direction will be discussed by the temperature dependence of the divided three components of the LaO layer, TAs layer, and the interlayer distance.

Investigation of tetragonal distortion in the PbTiO3–BiFeO3 system by high-temperature x-ray diffraction

1995 ◽  
Vol 10 (5) ◽  
pp. 1301-1306 ◽  
Author(s):  
V.V.S.S. Sai Sunder ◽  
A. Halliyal ◽  
A.M. Umarji
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Room Temperature ◽  
Tetragonal Distortion ◽  
X Ray Diffraction ◽  
Solution System ◽  
X Ray ◽  
Lattice Constants ◽  
Solid Solution System ◽  
Different Temperatures

Compositions in the (Pb1−xBix (Ti1−xFex)O3 solid solution system for x ⋚ 0.7 show unusually large tetragonal distortion. High-temperature x-ray diffraction was used to study the tetragonal distortion as a function of temperature (25–700 °C) for compositions (x = 0–0.7) using powders prepared by solid-state reaction in the above system. Large changes in the lattice parameters were observed over a narrow temperature range near Curie temperature (TC) for compositions near the morphotropic phase boundary (MPB) (x ≃ 0.7). Compositions near MPB showed a c/a ratio of 1.18 at room temperature. Polar plots of lattice constants at different temperatures indicated strong anisotropic thermal expansion with zero thermal expansion along the [201] direction.

Characterization of laser-diode end-pumped intracavity frequency doubled, passively Q-switched and mode-locked Nd:YVO4 laser

2005 ◽  
Vol 37 (2) ◽  
pp. 157-162 ◽  
Author(s):  
P.K. Mukhopadhyay ◽  
M.B. Alsous ◽  
K. Ranganathan ◽  
S.K. Sharma ◽  
P.K. Gupta ◽  
...  
Keyword(s):  
Laser Diode ◽  
Intracavity Frequency

Thermal Expansion Behavior of ZnSe and ZnS0.03Se0.97 Epilayers on GaAs at Temperatures in the Range, 25°C - 250°C

1994 ◽  
Vol 340 ◽  
Author(s):  
J. R. Kim ◽  
R. M. Park ◽  
K. S. Jones
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Lattice Mismatch ◽  
X Ray Diffraction ◽  
Thermal Expansion Behavior ◽  
Lattice Constants ◽  
Thermal Expansion Coefficients ◽  
Expansion Behavior ◽  
Expansion Coefficients ◽  
Lattice Matched

ABSTRACTThe thermal expansion behavior of ZnSe and ZnS0.03Se0.97 epilayers grown on GaAs has been investigated using high resolution X-ray diffraction at temperatures between room temperature and the growth temperature. The lattice parameters perpendicular and parallel to the surface were measured with the Bond's method. The lattice mismatch for a partially relaxed ZnSe layer was Δa(⊥)/a =2300 ppm and Δa(‖)/a = 2600 ppm at room temperature(R.T.) and Δa (⊥)/a =3600 ppm and Δa(‖)/a =2400 ppm at 250°C. For ZnS0.03Se0.97 which is almost lattice matched at R.T. to GaAs, Δa(⊥)/a =200 ppm, Δa(⊥)/a =20ppmatR.T. and Δa(⊥)/a =1400ppm, Δa(⊥)/a =50ppm at 250°C. The relaxed lattice constants were evaluated and the thermal expansion coefficients of relaxed ZnSe layers were found to vary from 7.8*10−6/°C at room temperature to 12.2*10−6/°C at 250°C and for ZnS0.03Se0.97 layers the variation was from 7.5*10−6/°C at R.T. to 11.7*10−6/°C at 250°C.

Processing, Microstructure, and Thermal Expansion Measurements for High Temperature Ru-Al-Cr B2 Alloys

2008 ◽  
Vol 1128 ◽  
Author(s):  
Yutaka Hashimoto ◽  
Norihiko L. Okamoto ◽  
Manuel Acosta ◽  
David R Johnson ◽  
Haruyuki Inui
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Directionally Solidified ◽  
Average Value ◽  
Heat Treated ◽  
Structural Applications ◽  
Cr System

AbstractThe B2 intermetallic compound RuAl has a melting temperature above 2000 °C and is a candidate for high temperature structural applications. A large extension of the B2 phase field is found in the Ru-Al-Cr system as was documented by the characterization of arc-melted and heat treated alloys. Two compositions consisting of Ru-35Al-19Cr and Ru-20Al-38Cr (at. %) were directionally solidified in an optical floating zone furnace. Depending upon the processing conditions, single phase, polycrystalline, B2 microstructures could be produced. The coefficient of thermal expansion (CTE) was measured from room temperature to 1250 °C for the Ru-20Al-38Cr alloy, and an average value of 11×10-6 K-1 was found. Additionally, the thermal conductivity was measured as 27 W/mK at room temperature for the Ru-20Al-38Cr B2 alloy and as 89 W/mK for binary RuAl.

scholarly journals Characterization of High-power DFB-MOPA Diode Lasers Emitting at 1064 nm

2019 ◽  
Vol 29 (1) ◽  
pp. 47
Author(s):  
Thanh-Phuong Nguyen
Keyword(s):  
Output Power ◽  
Laser Diode ◽  
High Power ◽  
Room Temperature ◽  
Beam Quality ◽  
Diode Lasers ◽  
Spectral Characteristics ◽  
Far Field ◽  
Optical Output

Detail characterization of the such laser diode is important for the applications. Electro-Optical and spectral characteristics of the high power 1064 nm DFB-MOPA lasers are investigated at room temperature as function of injection current. Beam quality is characterized by waist diameter and far-field divergence angle versus average optical output power. Beam propagation ratio M2 is defined at difference intensity levels from lateral beam profile giving more detail laser behaviors at high power.

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