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1.
Wenwei Ge Hong Liu Xiangyong Zhao Xiaobing Li Xiaoming Pan Di Lin Haiqing Xu Xiangping Jiang Haosu Luo 《Applied Physics A: Materials Science & Processing》2009,95(3):761-767
In this paper, a single crystal of 0.96Na0.5Bi0.5TiO3-0.04BaTiO3 with dimensions of Φ 30×10 mm was grown by the top-seeded-solution growth method. X-ray powder diffraction results show that the as-grown crystal
possesses the rhombohedral perovskite-type structure. The dielectric, piezoelectric and electrical conductivity properties
were systematically investigated with 〈001〉, 〈110〉 and 〈111〉 oriented crystal samples. The room-temperature dielectric constants
for the 〈001〉, 〈110〉 and 〈111〉 oriented crystal samples are found to be 650, 740 and 400 at 1 kHz. The (T
m, ε
m) values of the dielectric temperature spectra are almost independent of the crystal orientations; they are (306°C, 3718),
(305°C, 3613) and (307°C, 3600) at 1 kHz for the 〈001〉, 〈110〉 and 〈111〉 oriented crystal. The optimum poling conditions were
obtained by investigating the piezoelectric constants d
33 as a function of poling temperature and poling electric field. For the 〈001〉 and 〈110〉 crystal samples, the maximum d
33 values of 146 and 117 pC/N are obtained when a poling electric field of 3.5 kV/mm and a poling temperature of 80°C were applied
during the poling process. The as-grown 0.96Na0.5Bi0.5TiO3-0.04BaTiO3 crystal possesses a relatively large dc electrical conductivity, especially at higher temperature, having a value of 1.98×10−11 Ω−1⋅m−1 and 3.95×10−9 Ω−1⋅m−1 at 25°C and 150°C for the 〈001〉 oriented crystal sample. 相似文献
2.
High dose implantations (1016 ions/cm2) of antimony in silicon result in concentrations far above the solid solubility of antimony in silicon. Rutherford backscattering
was used to study the behaviour of damage and antimony concentration profiles for 〈100〉 and 〈111〉 substrates. The measurements
were performed for various annealing treatments, implantation temperatures and implantation energies. A crystal orientation
dependent outdiffusion of antimony towards the surface, a highly supersaturated phase of substitutional antimony at 600°C
and a strong reverse annealing effect at higher temperatures were found. 相似文献
3.
P. N. Chernykh N. G. Chechenin I. A. Sergachev M. A. Timofeev 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2011,5(1):65-69
Formation of rodlike structures elongated in the 〈100〉 and 〈010〉 directions of silicon crystal was observed during magnetron
codeposition of carbon and nickel on (100) silicon substrate with a natural oxide layer. Rodlike structures did not form during
deposition in similar conditions on (111) silicon substrate. It has been revealed that the rodlike structures represent epitaxial
nickel silicide precipitates. The results of experimental study of the composition, structure, and shape of forming silicide
clusters as a function of the silicon substrate orientation and the codeposited layer thickness are presented. 相似文献
4.
400 keV111In+ ions were implanted into CuO powder. After annealing at 570 K, more than 50% of the implants were found on substitutional
sites in the monoclinic CuO lattice. PAC-spectra taken below the Néel temperatureT
N≈230 K revealed a broadening of the quadrupole spectrum and additional satellite frequencies caused by combined electric and
magnetic hyperfine interaction. Assuming that the orientation of the electric field gradient is given by the point charge
model and taking the 〈010〉 direction of the supertransferred fieldB
tr in CuO from neutron diffraction, we find a Larmor frequency of ωL≈40 MHz corresponding toB
tr≈2.7 T at 60 K.
Supported in part by BMFT under contract FK213N54930. 相似文献
5.
Devraj Singh Dharmendra K. Pandey Pramod K. Yadawa 《Central European Journal of Physics》2009,7(1):198-205
The ultrasonic attenuation in thulium monochalcogenides TmX (X=S, Se and Te) has been studied theoretically with a modified Mason’s approach in the temperature and range 100 K to 300 K
along 〈100〉, 〈110〉 〈111〉 crystallographic directions. The thulium monochalcogenides have attracted a lot of interest due to
their complex physical and chemical characteristics. TmS, TmSe and TmTe are trivalent metal, mixed valence state, and divalent
semiconductor, respectively. Coulomb and Born-Mayer potential is applied to evaluate the second- and third-order elastic constants.
These elastic constants are used to compute ultrasonic parameters such as ultrasonic velocities, thermal relaxation time,
and acoustic coupling constants that, in turn, are used to evaluate ultrasonic attenuation. A comparison of calculated ultrasonic
parameters with available theoretical/experimental physical parameters gives information about classification of these materials.
相似文献
6.
M. N. Khlopkin 《JETP Letters》1999,69(1):26-30
The specific heat of a V3Si single crystal (T
c=17 K, H
c2=20 T) in magnetic fields up to 8 T isinvestigated experimentally for three orientations of the field relative to the crystallographic
directions — H∥〈001〉, H∥〈110〉, and H∥〈111〉. Both the upper critical magnetic field and the specific heat of the mixed state are observed to depend on the orientation
of the magnetic field relative to the crystallographic directions (anisotropy): The critical field reaches its maximum value
and the specific heat its minimum value in a field along the 〈001〉 direction. The anisotropy scale in both phenomena increases
as the magnetic field and reaches 3% in a 6 T field. The interrelationship of the upper critical field anisotropy and the
specific-heat anisotropy in type-II superconductors is studied. It is shown that the anisotropy of the specific heat in the
mixed state in weak fields can serve as a criterion for nontrivial pairing.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 1, 26–29 (10 January 1999) 相似文献
7.
Temperature dependence of ultrasonic attenuation due to phonon-phonon interaction and thermoelastic loss have been studied
in (NaCl-type) barium monochalcogenides [BaX, X = S, Se, Te], in the temperature range 50–500 K; for longitudinal and shear
modes of propagation along 〈100〉, 〈110〉, 〈111〉 directions. Second and third order elastic constants have been evaluated using
electrostatic and Born repulsive potentials and taking interactions up to next nearest neighbours. Gruneisen parameters, nonlinearity
constants, nonlinearity constants ratios and viscous drag due to screw and edge dislocations have also been evaluated for
longitudinal and shear waves at 300 K. In the present investigation, it has been found that phonon-phonon interaction is the
dominant cause for ultrasonic attenuation. The possible implications of results have been discussed.
The text was submitted by the authors in English. 相似文献
8.
E. M. Trukhanov I. D. Loshkarev K. N. Romanyuk A. K. Gutakovskii A. S. Ilin A. V. Kolesnikov 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(3):325-327
It is shown for (111) and (001) interfaces that at an identical degree of strain relaxation in semi-conductor epitaxial films,
the ratio of distances D between neighboring dislocations is D
(111)/D
(001) = 1.5. This allows us to establish that dislocation interface (7 7 10) contains partial 90° Shockley dislocations lying in
three directions of 〈110〉. 相似文献
9.
Ultrasonic attenuation for the longitudinal and shear waves due to phonon-phonon interaction and thermoelastic mechanism have
been evaluated in B2 structured intermetallic compounds AgMg, CuZr, AuMg, AuTi, AuMn, AuZn and AuCd along 〈100〉, 〈111〉 and
〈110〉 crystallographic directions at room temperature. For the same evaluations, second- and third-order elastic constants,
ultrasonic velocities, Grüneisen parameters, non-linearity parameter, Debye temperature and thermal relaxation time are also
computed. Although the molecular weight of these materials increases from AgMg to AuCd, the obtained results are affected
with the deviation number. Attenuation of ultrasonic waves due to phonon-phonon interaction is predominant over thermoelastic
loss. Results are compared with available theoretical and experimental results. The results with other well-known physical
properties are useful for industrial purposes.
相似文献
10.
Experimental studies of the dielectric properties in the nematic and isotropic phases of 4-cyanophenyl-4′-n-octylbenzoate
(8CPB) have been performed in the frequency range from 50 kHz to 100 MHz. The relaxation process related to the rotation around
the short molecular axis has been analysed. The results obtained have revealed that in the vicinity of the I-N phase transition,
the molecular subdiffusional rotation process occurs. It is connected with the pretransitional effects which are observed
both in the static and dynamic dielectric measurements. On the basis of the temperature dependence of the relaxation time
in the nematic and isotropic phases, the orientational order parameter 〈P2〉 has been determined. The values of 〈P2〉 obtained in this way have been compared with those evaluated from the measurements of the polarized electronic absorption
of the dichroic dye, dissolved as guest probe in the mesogenic host. 相似文献
11.
L. Schimmele A. Seeger W. Staiger W. Templ C. Baines A. Fritzsche M. Hampele D. Herlach K. Maier J. Major 《Hyperfine Interactions》1991,64(1-4):671-677
The longitudinalμ
+-spin relaxation rate has been measured on a high-purity spherical α-iron single crystal at temperaturesT down to 20 mK and in applied magnetic fieldsB
appl parallel to 〈111〉 up to 3 T. Only above 1 K can the data be satisfactorily described by one rate constantГ. At 1 T≤B
appl≤2 T and 50 mK≤T≤300 mK, oscillations (“wiggles”) were in addition superimposed on the longitudinal relaxation. A qualitative understanding
of the measurements may be achieved in terms of the increasing influence of internal stresses onμ
+ diffusion as the temperature is lowered. 相似文献
12.
The study reported in this paper contributes to better understanding the thermal oxidation effect on structural and optical
properties of polycrystalline silicon heavily in situ P-LPCVD films. The deposits, doped at levels 3×1019 and 1.6×1020 cm−3, have been elaborated from silane decomposition (400 mTorrs, 605°C) on monosilicon substrate oriented 〈111〉. The thermal
oxidation was performed at temperatures: 850°C during 1 hour, 1000, 1050, and 1100°C during 15 minutes. The XRD spectra analysis
pointed out significant 〈111〉 texture evolution, while in the case of 〈220〉 and 〈311〉 textures, the intensities are practically
invariant (variations fall in the uncertainty intervals). The optical characterizations showed that refractive index and absorption
coefficient are very sensitive to the oxidation treatment, mainly when the doping level is not very high. We think that atomic
oxygen acts as defects passivating agent leading to carriers’ concentration increasing. Besides, the optical behavior is modeled
in visible and near infrared, by a seven-term polynomial function n
2=f(λ
2), with alternate signs, instead of theoretically unlimited terms number from Drude’s model. It has been shown that fitting
parameters fall on Gaussian curves like they do in the theoretical model. 相似文献
13.
Using computer simulation, the failure mechanism of an fcc silver crystal under (111)〈$
\bar 2
$
\bar 2
〉 shear deformation is studied and the direction of unstable atomic displacement under the conditions of dynamic stability
violation is determined. It is shown that the most dangerous direction of atomic motion, which makes the crystal structurally
unstable, does not completely coincide with the 〈$
\bar 2
$
\bar 2
〉 direction lying in the (111) plane and has a component normal to the [111] direction. 相似文献
14.
The growth, movement and nature of outside dislocation, which propagate from heavily phosphorus (>1015 ions/cm2) implanted (111), (100), and (110) silicon layers into unimplanted outside regions by a compressive strain induced during
1100° C wet O2 annealing, are investigated using transmission electron microscopy and x-ray diffraction topography. Outside dislocations
are formed, mainly on (111) planes., by the glide motion of dislocation networks formed in implanted layers during early annealing.
This results in dislocations extending into the unimplanted areas to different degrees, in the order of, from the largest
to smallest, (111), (110), and (100) wafers. In (110) wafers, the [001] oriented dislocations in the implanted regions rise
to the surface at the implant and unimplant boundary. On the other hand, the [110] dislocations penetrate into the unimplanted
region. Two sets of orthogonal 〈110〉 oriented dislocations generated in (100) implanted wafers behave in the same manner as
the [001] dislocations in (110) wafers. Some sources of the compressive strain related to the generation of these dislocations
are discussed. 相似文献
15.
V. A. Baskov V. V. Kim B. I. Luchkov V. Yu. Tugaenko V. A. Khablo 《Bulletin of the Lebedev Physics Institute》2011,38(6):158-160
It is shown that the average charged particle multiplicity in electromagnetic showers induced by γ-rays with energies of 9–26 GeV in the tungsten crystal 1 mm thick (T = 77 K) oriented along the 〈111〉 axis approximately twofold increases in comparison with a misoriented crystal. 相似文献
16.
The polarization states of 〈111〉-cut Yb:YAG crystal microchip lasers were investigated by pumped with the elliptically polarized
pump beam from fiber-coupled laser-diode. The manipulated polarized lasers were achieved in laser-diode pumped Yb:YAG microchip
laser by controlling the crystalline-orientations in 〈111〉-growth Yb:YAG crystal. Generally elliptically polarized lasers
were obtained in laser-diode pumped Yb:YAG microchip lasers. However, crystalline-orientation manipulated linearly polarized
laser was obtained when six different sites with different crystalline orientations were set to parallel to the major axis
direction of the elliptically polarized pump beam. Six different sites in Yb:YAG crystal were separated with 30° and 90°,
which were responsible for the linearly polarized laser oscillations. Circularly polarized lasers were observed when a Yb:YAG
crystal was aligned to a special position between two sites responsible for linearly polarized laser oscillation. Effects
of the polarization states of pump source on the laser polarization states of Yb:YAG microchip lasers and polarization direction
of different polarized lasers with respect to Yb:YAG crystal rotation was addressed. 相似文献
17.
The method of transmission electron microscopy is used to study the dislocation structure in single crystals of the Ni
3
Fe ordered alloy for different degrees of strain. The [1812], [011], [111] and [001] single crystal orientations are examined.
The superdislocation splitting (r) is measured for different degrees of strain, distributions of r are constructed, and their
average values 〈r〉 are estimated. The 〈r〉-ε curves are constructed. With the use of the experimental r values, the effective
energy of antiphase boundaries ζ* is estimated.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 51–56, January, 2006. 相似文献
18.
Transition to single crystal of polycrystalline Si material underlying a Si crystal substrate of 〈100〉 orientation was obtained
via laser irradiation. The changes in the structure were analyzed by reflection high energy electron diffraction and by channeling
effect technique using 2.0 MeV He Rutherford scattering. The power density required to induce the transition in a 4500 ? thick
polycrystalline layer is about 70 MW/cm2 (50ns). The corresponding amorphous to single transition has a threshold of about 45 MW/cm2. 相似文献
19.
H.‐H. Klauß M. Hillberg W. Wagener M. Birke F.J. Litterst E. Schreier A. Kratzer G.M. Kalvius Y. Haga T. Suzuki 《Hyperfine Interactions》1997,104(1-4):177-180
We report on zero field and longitudinal field μSR experiments on a CeAs single crystal between 3.3 and 12 K. Below the antiferromagnetic
transition at 7.5 K a spontaneously precessing signal with a saturation frequency of \approx25 MHz representing the full sample
amplitude has been found. From an analysis of the field dependence of the relaxation rate of this signal in \langle 100\rangle
and \langle 110\rangle crystal orientation parallel to the muon spin and the applied longitudinal field, a \langle 100\rangle
orientation of the local field at the muon site is concluded. This supports an AF‐I single‐\veck magnetic ordering.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
V. V. Shagaev 《Physics of the Solid State》1998,40(11):1892-1895
Analytical expressions are derived for the derivatives of the frequencies of magnetostatic waves with respect to the external
magnetic field in anisotropic ferromagnetic films. Films having cubic anisotropy and 〈100〉, 〈110〉, and 〈111〉 surfaces are
analyzed in detail. The frequency-field relations are used in an experimental determination of the temperature coefficients
of the cubic anisotropy field and the saturation magnetization in an yttrium iron garnet film.
Fiz. Tverd. Tela (St. Petersburg) 40, 2089–2092 (November 1998) 相似文献