scholarly journals Подвижность носителей заряда в монокристалле и нанокерамике суперионного проводника Pb-=SUB=-1-x-=/SUB=-Sn-=SUB=-x-=/SUB=-F-=SUB=-2-=/SUB=- (x=0.2)

2019 ◽  
Vol 61 (11) ◽  
pp. 2044
Author(s):  
Н.И. Сорокин
Keyword(s):  
Solid Solution ◽  
Ionic Conductivity ◽  
Single Crystal ◽  
Single Crystals ◽  
Concentration Dependence ◽  
Crystal Form ◽  
Superionic Conductor ◽  
Charge Carriers ◽  
Ion Transfer ◽  
Anionic Charge

AbstractA crystallophysical model of ion transfer in the superionic Pb_1 – _ x Sn_ x F_2 conductor with a fluorite (CaF_2) structure is proposed. The concentration dependence of the ionic conductivity of Pb_1 – _ x Sn_ x F_2 single crystals and poly- and nanocrystals is analyzed. The single-crystal form of the superionic conductor is characterized by the highest conductivity. The mobility and concentration of anionic charge carriers in a single crystal and ceramics of Pb_1 – _ x Sn_ x F_2 ( x = 0.2) is calculated on the basis of structural and electrophysical data. The mobility of carriers μ_mob = 2.5 × 10^–6 cm^2/s V (at 293 K) in a single crystal is seven times higher than in nanoceramic. The concentration of carriers n _mob = 1.7 × 10^21 and 3.6 × 10^21 cm^3 (4.5 and 9.5% of the total number of anions) for a single crystal and nanoceramic, respectively. The comparison of isostructural Pb_0.8Sn_0.2F_2, Pb_0.67Cd_0.33F_2, and Pb_0.9Sc_0.1F_2.1 single crystals shows that anionic carriers have a maximum mobility in the β-PbF_2 and SnF_2 based solid solution.

The Effect of Solid Solution Impurities on Dislocation Nucleation in a (001) Mo – 1.5 at.% Ir Single Crystal

2010 ◽  
Vol 662 ◽  
pp. 85-93
Author(s):  
Sergey Dub ◽  
Igor Zasimchuk ◽  
Leonid Matvienko
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Shear Stress ◽  
Elastic Modulus ◽  
Single Crystal ◽  
Single Crystals ◽  
Free Volume ◽  
Dislocation Nucleation ◽  
Initial Portion ◽  
G 12

Mechanical properties of (001) Mo and (001) Mo – 1.5 at.% Ir single crystals have been studied by nanoindentation. It has been found that the iridium addition to molybdenum leads to an increase in both hardness and elastic modulus. An abrupt elasto-plastic transition (pop-in) at a depth of about 20 - 40 nm caused by dislocation nucleation in previously dislocation-free volume has been observed in the initial portion of the loading curve. It has shown that the Ir addition essentially affects the dislocation nucleation. Mean shear stress required for the dislocation nucleation increased from 10.8 GPa (G/12) for a Mo single crystal to 18.2 GPa (G/8) for the Mo – 1.5 at% Ir solid solution. Thus, the Ir solution in a Mo single crystal affects not only the resistance to the motion of dislocations (hardness) but the nucleation of them as well. The latter is likely to occur as a result of an increase in the structure perfection of the Mo – 1.5 at% Ir solid solution as compared to the pure Mo single crystal.

Switching Current in Pb(Zn1/3Nb2/3)O3-PbTiO3 Single Crystals

1999 ◽  
Vol 604 ◽  
Author(s):  
Uma Belegundu ◽  
Xiaohong Du ◽  
Kenji Uchino
Keyword(s):  
Solid Solution ◽  
Barium Titanate ◽  
Single Crystal ◽  
Single Crystals ◽  
Applied Field ◽  
Exponential Dependence ◽  
Polarization Reversal ◽  
Switching Current ◽  
Linear Fit ◽  
Two Phases

AbstractSwitching current measurements have been carried out on relaxorferroelectric single crystal-pure PZN, and the solid solution (1-x) Pb(Zni1/3 Nb2/3)O3 - x PbTiO3 with x= 0.04, 0.09, 0.10. Measurements have been done for crystallographic directions [001] and [111] for all these compositions. Switching times versus the applied field showed the following results. Pure PZN along [111] and 0.90PZN—O. 10PT along [001], and [111] showed an exponential dependence. Along [001] the PZN showed a linear fit. For solid solution single crystals-0.96PZN -0.04PT and 0.91PZN £ 0.09PT, a linear fit was obtained for the reciprocal switch times versus applied field for both the directions. If we draw a parallel picture with the reported barium titanate data, it appears that the polarization reversal is controlled by nucleation along [111]- spontaneous direction for PZN and [001], [111]for 0.90PZN - O.10PT. The mobility of the reversed domains controls the reversal along [001] for PZN and the solid solution single crystals with rhombohedral composition along [001] and [111]. The transient current curves showed two maximum points for crystals with x = 0.04 and 0.09. This is attributed to the co-existence of the two phases in 0.96PZN -0.04PT and 0. 91PZN - 0.09PT crystals.

Ionic Conductivity of Quasi-One-Dimensional Superionic Conductor KTiOPO4(KTP) Single Crystal

1993 ◽  
Vol 62 (1) ◽  
pp. 183-195 ◽  
Author(s):  
Shin-ichi Furusawa ◽  
Hisaaki Hayasi ◽  
Yoshihiro Ishibashi ◽  
Akio Miyamoto ◽  
Takatomo Sasaki
Keyword(s):  
Ionic Conductivity ◽  
Single Crystal ◽  
Superionic Conductor ◽  
One Dimensional

X-ray studies of thermal cycles in the transformation of potassium cyanide

1959 ◽  
Vol 252 (1271) ◽  
pp. 445-456 ◽  
Keyword(s):  
Solid Solution ◽  
Single Crystals ◽  
Potassium Cyanide ◽  
Crystal Form ◽  
Sodium Cyanide ◽  
Normal Cycle ◽  
Temperature Changes ◽  
X Ray ◽  
Cyclic Temperature ◽  
Thermodynamic Transformations

Single crystals of pure potassium cyanide, and of potassium cyanide containing various amounts of sodium cyanide in solid solution, have been subjected to cyclic temperature changes traversing the thermaltransformation at around — 110 °C. By means of Laue and Bragg photographs, persistence of the crystal axes has been observed in a ‘normal cycle’ high → low → high, but a metastable crystal form was also produced by a particular sequence of changes. There was considerable hysteresis in the transformation of single crystals. Introducing lattice disturbances by incorporating sodium cyanide in solid solution broadened the transformation. Co-existence was observed of various domains of the low-temperature form in ‘hybrid’ single crystals; there was also evidence for the co-existence of domains of the low- and high-tem perature forms over a range of temperatures. These results are discussed in relation to theories of continuous thermodynamic transformations in solids.

Ionic Conductivity of Li2ZnTi3O8 Single Crystal

2011 ◽  
Vol 497 ◽  
pp. 26-30 ◽  
Author(s):  
Shinichi Furusawa ◽  
Hiroshi Ochiai ◽  
Khoji Murayama
Keyword(s):  
Ionic Conductivity ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Powder Diffraction ◽  
Floating Zone ◽  
Zinc Titanate ◽  
X Ray ◽  
Temperature Range ◽  
First Time

Single crystals of lithium zinc titanate (Li2ZnTi3O8) were grown in a double-mirror type optical floating-zone furnace for the first time. Single crystals were characterized by X-ray powder diffraction and Laue measurements. The ionic conductivity of the single crystals was measured in the temperature range of 400–700 K. Below 600 K, the ionic conductivity of the single crystal is one to two orders of magnitude higher than that of polycrystalline Li2ZnTi3O8. In the temperature range of 550–600 K, the temperature dependence of the ionic conductivity shows non-Arrhenius behaviour.

The mechanical behaviour of single crystals of certain face-centred cubic metals

1951 ◽  
Vol 244 (880) ◽  
pp. 177-203 ◽  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Room Temperature ◽  
Critical Shear Stress ◽  
Crystal Form ◽  
Surface Contamination ◽  
Cube Root ◽  
Impurity Atoms ◽  
Gold Silver ◽  
Normal Diffusion

Single crystal rods of gold, silver and nickel have been prepared from the melt by a modified cooling method. The three metals differ in that the gold is very pure and has no surface contamination; the silver is very pure and the surface normally shows contamination; the nickel is markedly less pure. These three features find expression in the results. The stress-glide relationship has been investigated over the whole range to fracture, special attention being paid to the region of small glide. At very small glides the results show certain variations attributed to metastable conditions. For pure metals at low temperatures a region of easy glide has been established, which is absent in nickel. Considerations of the variation of hardening with temperature at constant glide show that, at moderate glide, rise of temperature at low temperature promotes hardening, but rise of temperature at high temperature leads to decrease of hardening. From these results it is concluded that in metals without notable impurity glide is due to two distinct processes, first the initiation of glide planes, which temperature agitation tends to check, and secondly to glide proceeding on planes already initiated, which temperature agitation tends to promote. The surface contamination of silver single crystals which takes place by exposure to air at room temperature raises the critical shear stress somewhat, but has a much more marked effect on the hardening after some tens of per cent of glide has taken place, which is attributed to diffusion of the impurity atoms, probably oxygen, taking place during the travel of the dislocations. This is distinct from normal diffusion, which is negligible at room temperature. The results on the effect of surface contamination explain abnormalities previously noted with silver. The close connexion of asterism and hardening is exhibited in the results obtained with gold and silver. In particular, silver in the region of easy glide shows very small asterism, even at large glide. The cube root of the breaking stress of all metals in single-crystal form has been found to show a linear relationship with temperature.

scholarly journals Кристаллофизическая модель электропереноса в суперионном проводнике Pb-=SUB=-1-x-=/SUB=-Sc-=SUB=-x-=/SUB=-F-=SUB=-2+x-=/SUB=- (x=0.1)

2018 ◽  
Vol 60 (4) ◽  
pp. 710
Author(s):  
Н.И. Сорокин
Keyword(s):  
Electrical Conductivity ◽  
Ionic Conductivity ◽  
Single Crystals ◽  
Room Temperature ◽  
Charge Carriers ◽  
Bulk Conductivity ◽  
Characteristic Parameters ◽  
Calculated Concentration ◽  
Fluorite Type ◽  
Mobile Ions

AbstractThe frequency (ν = 10^–1–107 Hz) dependences of electrical conductivity σ(ν) of single crystals of superionic conductor Pb_0.9Sc_0.1F_2.1 (10 mol % ScF_3) with fluorite type structure (CaF_2) in the temperature range 153–410 K have been investigated. The static bulk conductivity σ_ dc =1.5 × 10^–4 S/cm and average hopping frequency ν_ h = 1.5 × 10^7 Hz of charge carriers (mobile ions F^−) at room temperature (293 K) have been defined from the σ_ dc (ν) experimental curves. Enthalpies of thermoactivated processes of ionic conductivity σ_ dc ( T ) (Δ H _σ = 0.393 ± 0.005 eV) and dielectric relaxation ν_ h ( T ) (Δ H _h = 0.37 ± 0.03 eV) coincide within their errors. A crystal-physical model of fluorine-ion transport in a Pb_0.9Sc_0.1F_2.1 crystal lattice has been proposed. The characteristic parameters of charge carriers have been calculated: concentration n _mob = 2.0 × 10^21 cm^−3, the distance of the hopping d ≈ 0.5 nm and mobility μ_mob = 4.5 × 10^−7 cm^2/s V (293 K).

scholarly journals Кристаллофизическая модель ионного переноса в монокристаллах супериоников Ba-=SUB=-1-x-=/SUB=-La-=SUB=-x-=/SUB=-F-=SUB=-2+x-=/SUB=- и Ca-=SUB=-1-x-=/SUB=-Y-=SUB=-x-=/SUB=-F-=SUB=-2+x-=/SUB=-

2021 ◽  
Vol 63 (10) ◽  
pp. 1485
Author(s):  
Н.И. Сорокин ◽  
Д.Н. Каримов
Keyword(s):  
Single Crystals ◽  
Solid Solutions ◽  
Mechanical Characteristics ◽  
Structural Data ◽  
Charge Carriers ◽  
Superionic Conductors ◽  
Ion Transfer ◽  
Directional Crystallization ◽  
Space Group ◽  
Galvanic Cells

Based on the electrophysical and structural data, a crystallophysical model of ion transfer in superionic conductors Ba1-xLaxF2 + x and Ca1-xYxF2 + x (space group Fm3m) is proposed, in which the charge carriers are mobile interstitial ions Fmob-, formed as a result of heterovalent substitutions of fluorite fragments [M14F64] (M = Ca, Ba) into structural clusters [M8R6F69] (R = La, Y). Single crystals of solid solutions Ca1-xYxF2 + x (0.02≤ x≤0.16) and Ba1-xLaxF2 + x (x = 0.31) were obtained by directional crystallization of the melt. The mobilities of ionic carriers in isostructural superionics Ba0.69La0.31F2.31, Ca0.84Y0.16F2.16, Pb0.67Cd0.33F2, and Pb0.9Sc0.1F2.1 are compared. Crystals Ba1-xLaxF2 + x and Ca1-xYxF2 + x with improved conductometric and mechanical characteristics are promising for replacing the traditional CaF2 electrolyte in galvanic cells for thermodynamic research of chemicals.

Investigation of Pu Incorporation into Zircon Single Crystal

2004 ◽  
Vol 824 ◽  
Author(s):  
John M. Hanchar ◽  
Boris E. Burakov ◽  
Maria V. Zamoryanskaya ◽  
Vladimir M. Garbuzov ◽  
Alexander A. Kitsay ◽  
...  
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Single Crystals ◽  
Unit Cell ◽  
Additional Research ◽  
Powdered Sample ◽  
Unit Cell Parameters ◽  
Flux Method ◽  
Cell Parameters ◽  
Zircon Structure

AbstractIn order to obtain Pu-doped zircon, (Zr,Pu)SiO4, with a maximum Pu content in the form of solid solution, zircon single crystals have been grown using the flux method from starting materials overloaded with Pu. The crystals obtained ranged from 0.2-0.5 to 3.5-4.5 mm in size, are transparent, and characterized by deep pink-brown color. No inclusions of separate Pu phases were observed in the crystals. The distribution of Pu in crystals is zoned and the Pu content varying from approximately 5 to 14 wt.% el. The zircon unit cell parameters calculated from XRD data of bulk powdered sample were: a=6.620(1); c=5.989(2). The results obtained allow us to conclude that the capacity of the zircon structure to incorporate Pu exceeds 10 wt.% el.; however, additional research is required to study the extent of solid solution, (Zr,Pu)SiO4, at higher Pu contents.

The observation of defects on (100) CdTe surfaces by chemical etching

1992 ◽  
Vol 50 (2) ◽  
pp. 1424-1425
Author(s):  
M.E. Lee
Keyword(s):  
Single Crystal ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Chemical Etching ◽  
Crystalline Perfection ◽  
Crystalline Defects ◽  
High Incidence ◽  
Crystallographic Defects ◽  
Cdznte Substrates ◽  
Device Technology

The crystalline perfection of bulk CdTe substrates plays an important role in their use in infrared device technology. The application of chemical etchants to determine crystal polarity or the density and distribution of crystallographic defects in (100) CdTe is not well understood. The lack of data on (100) CdTe surfaces is a result of the apparent difficulty in growing (100) CdTe single crystal substrates which is caused by a high incidence of twinning. Many etchants have been reported to predict polarity on one or both (111) CdTe planes but are considered to be unsuitable as defect etchants. An etchant reported recently has been considered to be a true defect etchant for CdTe, MCT and CdZnTe substrates. This etchant has been reported to reveal crystalline defects such as dislocations, grain boundaries and inclusions in (110) and (111) CdTe. In this study the effect of this new etchant on (100) CdTe surfaces is investigated.The single crystals used in this study were (100) CdTe as-cut slices (1mm thickness) from Bridgman-grown ingots.

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