TITLE:
Neutron Diffraction Study of Self-Curing and Self-Crystallization Phenomena of Low-Temperature Dehydrogenating Products of Powder Crystals of Rare-Earth Metals Trihydroxides
AUTHORS:
Khidirov Irisali
KEYWORDS:
Hydrogen Termoemission; Rare-Earth Metals Trihydrooxides; Neutron Diffraction; High Vacuum; Continuous Evacuation; Metastable “Trioxide” R[O3]
JOURNAL NAME:
Journal of Crystallization Process and Technology,
Vol.3 No.4,
October
25,
2013
ABSTRACT: 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 Тev. which is lower than recrystallization Тrecrys. or
disintegration (Tdisinteg.) temperature of this crystal: Тev. Тrecrys. Tdisineg.. By neutron
diffraction it is found that low- temperature (Тevacuation = 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: R3+O6-.
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[O3] 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[O3] to transform into stable form R(OH)3 by
selective bonding of hydrogen from the hydrogen-containing environment allowing implication of Pr[O3] 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.