Structure of Partly Vacuum Extracted MgH2 Samples

2017 ◽  
Vol 380 ◽  
pp. 35-38
Author(s):  
Stepan Alexandrovich Lushnikov ◽  
Tatyana Victorovna Filippova ◽  
Ivan Anatolievich Bobrikov
Keyword(s):  
Low Temperature ◽  
Neutron Diffraction ◽  
High Stability ◽  
Diffraction Method ◽  
Ambient Conditions ◽  
Hydrogen Distribution ◽  
Hydrogen Atoms ◽  
Neutron Data ◽  
Neutron Diffraction Method

The structure of partly desorbed and quenched samples of MgH2 has been investigated by the neutron diffraction method. In ambient conditions a partly desorbed sample demonstrates high stability, while the same sample quenched at low temperature decomposed into Mg after several days. Obtained neutron data showed that all studied samples contain coexisting Mg and MgH2 phases. Hydrogen distribution for both quenched and non-quenched samples is similar. Hydrogen atoms occupied sites predominantly in the MgH2 lattice, whereas Mg lattice is free of the hydrogen.

Hydrogen Distribution in Partly Desorbed MgH2 Samples

2019 ◽  
Vol 22 ◽  
pp. 34-38
Author(s):  
Stepan Alexandrovich Lushnikov ◽  
Tatyana Victorovna Filippova ◽  
Ivan Anatolievich Bobrikov
Keyword(s):  
Low Temperature ◽  
Diffraction Method ◽  
Temperature Treatment ◽  
Vacuum Extraction ◽  
Hydrogen Distribution ◽  
Hydrogen Atoms ◽  
Neutron Data ◽  
Low Temperature Treatment ◽  
Diffusion Of Hydrogen ◽  
Neutron Diffraction Method

The structure of MgH2 samples has been investigated by the neutron diffraction method at room temperature and 5 K. Samples of MgH2 have been prepared with vacuum extraction technique at high temperature. Obtained neutron data demonstrated that samples contain coexisting Mg and MgH2 phases in different rate. The distribution of hydrogen atoms in the structure of the samples is comparable at both temperatures. Collected neutron data and results of X-ray analysis show that microstructure of the samples is different at room and at low temperature. Non-stability of partly desorbed MgH2 samples after low temperature treatment has been discussed on basis of different diffusion of hydrogen atoms in varied microstructure.

Residual Stress Evaluation of Ni Based Weld Metal Using Neutron Diffraction Method

2006 ◽  
Vol 524-525 ◽  
pp. 697-702 ◽  
Author(s):  
Shinobu Okido ◽  
Hiroshi Suzuki ◽  
K. Saito
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Neutron Diffraction ◽  
Weld Metal ◽  
Diffraction Method ◽  
Fem Analysis ◽  
Butt Weld ◽  
Stress Evaluation ◽  
Neutron Diffraction Method

Residual stress generated in Type-316 austenitic stainless steel butt-weld jointed by Inconel-182 was measured using a neutron diffraction method and compared with values calculated using FEM analysis. The measured values of Type-316 austenitic stainless steel as base material agreed well with the calculated ones. The diffraction had high intensity and a sharp profile in the base metal. However, it was difficult to measure the residual stress at the weld metal due to very weak diffraction intensities. This phenomenon was caused by the texture in the weld material generated during the weld procedure. As a result, this texture induced an inaccurate evaluation of the residual stress. Procedures for residual stress evaluation to solve this textured material problem are discussed in this paper. As a method for stress evaluation, the measured strains obtained from a different diffraction plane with strong intensity were modified with the ratio of the individual elastic constant. The values of residual stress obtained using this method were almost the same as those of the standard method using Hooke’s law. Also, these residual stress values agreed roughly with those from the FEM analysis. This evaluation method is effective for measured samples with a strong texture like Ni-based weld metal.

Local Structure of the Amorphous Ni25Zr75-Alloy by Using the Isotope-Substitution Neutron Diffraction Method

1991 ◽  
Vol 46 (11) ◽  
pp. 951-954
Author(s):  
W.-M. Kuschke ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Neutron Diffraction ◽  
Local Structure ◽  
Short Range ◽  
Short Range Order ◽  
Diffraction Method ◽  
Isotopic Substitution ◽  
Isotope Substitution ◽  
Coordination Numbers ◽  
Structure Factors ◽  
Neutron Diffraction Method

AbstractUsing neutron diffraction as well as the method of isotopic substitution the partial Bhatia-Thornton as well as the partial Faber-Ziman structure factors of amorphous Ni25Zr75 were determined. A compound forming tendency was found. The atomic distances, partial coordination numbers, and the chemical short range order parameter are evaluated.

scholarly journals Crystal structure analysis of LiN(DxH1-x)4SO4by neutron diffraction

2014 ◽  
Vol 70 (a1) ◽  
pp. C1703-C1703
Author(s):  
Shin Ae Kim ◽  
Chang-Hee Lee
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Diffraction Method ◽  
Crystal Structure Analysis ◽  
Ferroelectric Materials ◽  
Lattice Parameters ◽  
Least Square ◽  
Intensity Data ◽  
Hydrogen Atoms ◽  
Neutron Intensity

The crystal structure of Li(ND4)SO4 was analysed by neutron diffraction method. The crystal is a partially deuterated Li(NH4)SO4 and one of the ferroelectric materials with hydrogen atoms. The crystal is orthorhombic at room temperature with lattice parameters of a=5.2773(5) Å, b=9.124(2) Å, c=8.772(1) Å and Z=4. Neutron intensity data were collected on the Four-Circle Diffractometer (FCD) at HANARO in Korea Atomic Energy Research Institute. The structure was refined by full-matrix least-square to final R value of 0.049 for 745 observed reflections by neutron diffraction. All atomic positions of four hydrogen atoms at NH4 and the occupation factors of D and H were refined. From these results we obtained the average chemical structure of this sample, LiND3.05H0.95SO4. Five years later, neutron intensity data were collected and analysed once more with same crystal. The crystal is orthorhombic but with different lattice parameters, or hexagonal. We will report and discuss these results in this presentation.

Neutron diffraction study of the crystal structure of TlInSe2 at high pressure

2019 ◽  
Vol 33 (15) ◽  
pp. 1950149 ◽  
Author(s):  
N. T. Mamedov ◽  
S. H. Jabarov ◽  
D. P. Kozlenko ◽  
N. A. Ismayilova ◽  
M. Yu. Seyidov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Neutron Diffraction ◽  
Tetragonal Phase ◽  
Unit Cell Volume ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
Neutron Diffraction Study ◽  
Pressure Derivative ◽  
Neutron Diffraction Method

We have investigated the crystal structure of strongly anisotropic semiconductor TlInSe2 by neutron diffraction method under high pressure upto P = 3.3 GPa. It was shown that the tetragonal phase of TlInSe2 crystal (the space group I4/mcm) is stable in the whole investigated range of pressure. The lattice parameters dependence of the pressure and the unit cell volume are obtained, the linear coefficients of compressibility and the bulk moduli are calculated. At the low pressure, obtained value of compressibility for the lattice parameter a is k[Formula: see text] = 14.23 × 10[Formula: see text] GPa[Formula: see text] and for c is k[Formula: see text] = 5.93 × 10[Formula: see text] GPa[Formula: see text]. Obtained values for bulk modulus B0 and its pressure derivative B[Formula: see text] in tetragonal phase are 30(7) GPa and 4(1), respectively.

Investigation of the residual stress in UO2-Mo composites via a neutron diffraction method

2020 ◽  
Vol 46 (10) ◽  
pp. 15889-15896 ◽  
Author(s):  
Liang Cheng ◽  
Rui Gao ◽  
Biaojie Yan ◽  
Changsheng Zhang ◽  
Ruiwen Li ◽  
...  
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Diffraction Method ◽  
Neutron Diffraction Method

scholarly journals Magnetic Structure of Inorganic–Organic Hybrid (C6H5CH2CH2NH3)2MnCl4 Using Magnetic Space Group Concept

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1980
Author(s):  
Garam Park ◽  
In-Hwan Oh ◽  
J. M. Sungil Park ◽  
Seungsoo Hahn ◽  
Seong-Hun Park
Keyword(s):  
Neutron Diffraction ◽  
Magnetic Structure ◽  
Diffraction Method ◽  
Translation Group ◽  
Space Group ◽  
Organic Hybrid ◽  
Group Concept ◽  
Representation Method ◽  
Nuclear Cell ◽  
Neutron Diffraction Method

Previously, we reported that inorganic–organic hybrid (C6H5CH2CH2NH3)2MnCl4 (Mn-PEA) is antiferromagnetic below 44 K by using magnetic susceptibility and neutron diffraction measurements. Generally, when an antiferromagnetic system is investigated by the neutron diffraction method, half-integer forbidden peaks, which indicate an enlargement of the magnetic cell compared to the chemical cell, should be present. However, in the case of the title compound, integer forbidden peaks are observed, suggesting that the size of the magnetic cell is the same as that of the chemical cell. This phenomenon was until now only theoretically predicted. During our former study, using an irreducible representation method, we suggested that four spin arrangements could be possible candidates and a magnetic cell and chemical cell should coincide. Recently, a magnetic structure analysis employing a magnetic space group has been developed. To confirm our former result by the representation method, in this work we employed a magnetic space group concept, and from this analysis, we show that the magnetic cell must coincide with the nuclear cell because only the Black–White 1 group (equi-translation or same translation group) is possible.

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