Localization of hydrogen atoms in rare earth metal trihydroxides R (OH)3

Khidirov, I.; T, Venizelos E. Sourmelis

doi:10.1002/pssa.2211400231

Cited by 11 publications

(31 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Samples composition was determined by chemical analysis and by minimizing of the R-factors of structure determination based on neutron diffraction patterns. These results are consistent with the results of other authors [2,3]. All of them have lattice parameters close to each other, which are identical with values resulted in [2,3].…”

Section: Experiments Techniquessupporting

confidence: 93%

“…These results are consistent with the results of other authors [2,3]. All of them have lattice parameters close to each other, which are identical with values resulted in [2,3].…”

Section: Experiments Techniquessupporting

confidence: 93%

“…Diffraction patterns of other REM trihydroxides were similar to that of Pr(OH) 3 . Since according to [2] and data of the present work, all REMs R(OH) 3 trihydrooxides having UCl 3 -type hexagonal structure (space group P6 3 /m) with lattice parameters close to each other, further in the text for an illustration we will use neutron diffraction pattern of one of them.…”

Section: Resultsmentioning

confidence: 72%

“…The least R-factors on Bragg maxima at calculation of the neutron diffraction pattern by method of Ritveld were obtaining for the model in the frame of P6 3 /m space group. The difference of experimental and calculated intensities of the neutron diffraction pattern of the Pr (OH) 3 in the frame of P6 3 /m space group is also presented in Figure 1(a). The structural characteristics of the R(OH) 3 samples are given in Table 1.…”

Section: Resultsmentioning

confidence: 99%

“…This substance is stable only at relatively low temperature and in the medium free of hydrogen. In the air at room temperature, this substance, interacting with water molecules, gradually turns to trihyrdoxides R(ОH) 3 again, compensating excessive negative charge by means of three hydrogen atoms, trapping them from atmospheric water molecules, and releasing oxygen molecules. The aim of this work is to do more detailed study of the hydrogen thermoemission out of crystal lattice of powder rare earth metal (REM) trihydroxides R (OH) 3 , (R is La, Pr, Nd) and kinetics of self-curing and self-crystallisation of low-temperature dehydrogenating products of REM trihydroxides in atmospheric conditions at room temperature by neutron diffraction.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Neutron Diffraction Study of Self-Curing and Self-Crystallization Phenomena of Low-Temperature Dehydrogenating Products of Powder Crystals of Rare-Earth Metals Trihydroxides

Khidirov¹

2013

JCPT

View full text Add to dashboard Cite

The phenomenon of hydrogen thermoemission out of a crystal lattice of powder rare-earth metals trihydrooxides R(OH) 3 (R is La, Pr, Nd) was found. The hydrogen thermoemission out of a crystal lattice is partial or full removal of hydrogen out of the crystal lattice of powder hydrogen-containing crystal without change of symmetry of such crystal at continuous evacuation of high vacuum at evacuation temperature of Т ev. which is lower than recrystallization Т recrys. or disintegration (T disinteg. ) temperature of this crystal: Т ev. < Т recrys. < T disineg. . By neutron diffraction it is found that lowtemperature (Т evacuation = 400 -420 K ) removal of hydrogen (by hydrogen thermoemission) out of a crystal lattice of trihydrooxide R(OH) 3 under continuous high vacuum evacuating makes possible to obtain metastable "trioxide" R[O] 3 . Existence of such substance contradicts to the valence law (oxygen is bivalent and Pr is trivalent in hydroxides). Such "trioxide" has a superfluous negative charge: R 3+ O 6− . So they aspire to "capture" three more protons (hydrogen ions) from a water molecules. Obviously, this substance can be stable at low temperatures and in the mediums, which are not containing hydrogen. In the air at room temperature this substance, most likely, interacting with water molecules, gradually again turns into trihydroxide R(OH) 3 , compensating the superfluous negative charge by three hydrogen atoms. From this it follows that substance R [O 3 ] can simultaneously be an absorber of hydrogen and generator of oxygen at atmospheric conditions and in any mediums which contains water molecules, without any prior processing like heating or high pressure. Thus, the obtained material, without any prior processing like heating or high pressure, can simultaneously be oxygen generator and hydrogen accumulator in any mediums characteristic of R [O 3 ] to transform into stable form R(OH) 3 by selective bonding of hydrogen from the hydrogen-containing environment allowing implication of Pr [O 3 ] as the hydrogen selective absorber. Separation (by low-temperature removal) of hydrogen out of R(OH) 3 lattice can again lead to restoration of its capabilities to be a simultaneous hydrogen accumulator and oxygen generator in a medium containing water molecules.

show abstract

Section: Experiments Techniquessupporting

confidence: 93%

“…These results are consistent with the results of other authors [2,3]. All of them have lattice parameters close to each other, which are identical with values resulted in [2,3].…”

Section: Experiments Techniquessupporting

confidence: 93%

Section: Resultsmentioning

confidence: 72%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations