65 research outputs found
A search for disordered (glassy) phase in solid 3He deformed in situ
A disordered (glassy) state has been searched in solid 3He deformed in the
course of experiment employing precise measurements of pressure. The analysis
of the temperature dependence of the crystal pressure measured at a constant
volume shows that the main contribution to the pressure is made by the phonon
subsystem, the influence of the disordered phase being very weak. Annealing of
the deformed crystal does not affect this state. The results obtained differ
greatly from the corresponding data for solid 4He measured in the region of
supersolid effects where a pressure excessive in comparison to the phonon one
was registered. The excess pressure had a quadratic dependence on temperature,
which is typical of a disordered system. Absence of the excess pressure in
solid 3He is unclear yet, some speculative interpretations are suggested.Comment: 9 pages, 4 figure
Optically-stimulated desorption of 'hot' excimers from pre-irradiated Ar solids
Electronically-induced desorption from solid Ar pre-irradiated by a
low-energy electron beam was investigated by activation spectroscopy methods -
photon-stimulated exoelectron emission and photon-stimulated luminescence in
combination with spectrally-resolved measurements in the VUV range of the
spectrum. Desorption of vibrationally excited argon molecules Ar2^*(v) from the
surface of pre-irradiated solid Ar was observed for the first time. It was
shown that desorption of 'hot' Ar2^*(v) molecules is caused by recombination of
self-trapped holes with electrons released from traps by visible range photons.
The possibility of optical stimulation of the phenomenon is evidenced.Comment: The complete version of the paper will be published in Fiz. Nizk.
Temp. (Low Temp. Phys.
On the electric activity of superfluid systems
The Keldysh's theory of superfluidity of rarefied electron-hole gas is
generalized to a case of possible pair polarizability. It was shown that
inhomogeneity of the system leads to dipole moment which is proportional to the
density gradient. The dipole moment appears also near boundaries of the system.
It was determined that quantized vortices in a magnetic field carry a real
electric charge. In He II at H=10 T and helium rotation velocity
s the charge density is about cm, where is the
electron charge.Comment: 5 pages V. 2: replaced incorrect g valu
Crowdion dynamics in a nonuniformly deformed three-dimensional crystal
The problem of crowdion motion is formulated and analyzed as a
dynamical problem of a three-dimensional crystal lattice formed by
atoms of several kinds, which interact with each other by means of
short-range pair potentials. It is explained that in order for the
the crowdion excitations of the close-packed atomic rows to be
distinguishable against the background of small dynamic deformations
of the crystal as a whole, the microscopic parameters of the crystal
structure must meet certain stated requirements.
The equation of motion of a crowdion in an arbitrary elastic strain
field of the crystal is derived in the Lagrangian formalism.
Expressions are obtained which relate the effective mass and the rest
energy of a crowdion with the geometric and force parameters of the crystal
lattice
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