共查询到20条相似文献,搜索用时 31 毫秒
1.
L. Jentjens K. Peithmann K. Maier H. Steigerwald T. Jungk 《Applied physics. B, Lasers and optics》2009,95(3):441-445
Irradiation of 5% magnesium-doped lithium niobate crystals (LiNbO3:Mg) with high-energy, low-mass 3He ions, which are transmitted through the crystal, changes the domain reversal properties of the material. This enables easier
domain engineering compared to non-irradiated material and assists the formation of small-sized periodically poled domains
in LiNbO3:Mg. Periodic domain structures exhibiting a width of ≈520 nm are obtained in radiation-damaged sections of the crystals.
The ferroelectric poling behavior between irradiated and non-treated material is compared. 相似文献
2.
V. Bermúdez L. Huang D. Hui S. Field E. Diéguez 《Applied Physics A: Materials Science & Processing》2000,70(5):591-594
Non-congruent LiNbO3 crystals has been used to determine the influence of the intrinsic defect density in the ferroelectric domain inversion mechanism.
The poling processes have been carried out either at high temperature or at RT throughout the electric-field-poling technique.
It is shown that the coercive field of LiNbO3 crystals is strongly influenced by the intrinsic defect density in the crystals. Moreover it is shown that it is possible
to realign the ferroelectric domain structure of near-stoichiometric LiNbO3 crystals to prepare periodic poled structures which allows second harmonic generation at shorter wavelengths than with congruent
crystals at a fixed wavelength.
Received: 6 July 1999 / Accepted: 24 November 1999 / Published online: 24 March 2000 相似文献
3.
J. Erhart 《Phase Transitions》2013,86(12):989-1074
This paper concerns the problem of orientations of domain walls in ferroelastic and/or ferroelectric single crystals. They are specified on the basis of elastic compatibility of the neighbouring domains. Results are presented in form of tables, which make it possible to find spontaneous tensors (i.e. strain and polarization) for each domain state in any ferroelastic and/or ferroelectric species. Domain wall orientations are listed in tables for all combinations of domain states. For each domain wall orientation, their charge or neutrality is indicated. Results are summarized in comprehensive table including numbers of possible domain states, domain wall types (W ∞, W f , S) and their charge or neutrality. Domain pairs with non-permissible domain walls (R case) are also specified. 相似文献
4.
R. V. Gainutdinov T. R. Volk O. A. Lysova I. I. Razgonov A. L. Tolstikhina L. I. Ivleva 《Applied physics. B, Lasers and optics》2009,95(3):505-512
The recording of microdomains and regular 1D- (linear) and 2D- (square) domain arrays was performed in SBN crystals by means
of applying low (within 10 V) DC voltages to an AFM tip. The ferroelectric phenomena under AFM-tip fields (P–E hysteresis loops, the domain dynamics, etc.) agree qualitatively with the polarization processes observed at the macroscopic
level and reveal peculiarities obviously related to the relaxor origin of SBN crystals. Particularly, the domain formation
and the domain-wall lateral motion occur under fields much lower than E
c
, which founds no explanation in terms of the model approach to the ferroelectric switching. The formation of linear and square
domains results from overlapping closely spaced individual domains. For the first time a drastic dependence of the temporal
stability on the domain topology was found. Namely, at identical exposure conditions of recording, the lifetimes of individual
domains, domain lines, and domain squares (“chessboards”) are, respectively, several minutes, tens of hours, and no less than
a month. 相似文献
5.
6.
The domain states and phase transitions in 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 single crystals were investigated by studying their relative permittivity under various dc bias at constant heating and cooling rates. The orientation dependence of the bias field effect was revealed by examining the temperature dependence of relative permittivity as a function of crystal orientation (the 〈111〉, 〈011〉 and 〈001〉 directions) and dc bias field. The crystals basically have a macrodomain rhombohedral ferroelectric state in the ferroelectric phase under zero dc bias. External bias field could modulate the domain state and induce a stable macrodomain state in the crystals. Also, it is proposed that the dc bias applied along the 〈001〉 or 〈011〉 direction could induce a tetragonal ferroelectric phase or an orthorhombic ferroelectric phase, respectively, in an intermediate temperature range. 相似文献
7.
Abstract Several Tl0 (6s26p 1)-type paramagnetic centers, produced by low temperature X-ray irradiation, were observed and studied by electron spin resonance (ESR) in the orthorhombic ferroelectric phase of thallium doped Rb2ZnCl4 crystals. The centers were formed by electron trapping at Tl+ ions localized substitutionally at Rb+ sites. The number and properties of the observed centers account for the tripling of the unit cell in the ferroelectric phase. 相似文献
8.
V. V. Gorbatenko V. I. Kudriash B. N. Prasolov S. A. Gorbatenko 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(8):1041-1046
Harmonic analysis of repolarization in A 2 BX 4-group crystals in the ferroelectric phase near phase-transition temperature T c is used to separate the contributions to the harmonic-component amplitudes in the output signal of a Sawyer-Tower circuit from charging the reference capacitor with capacitive and conductive current through such a crystal. Harmonic analysis of dielectric hysteresis loops obtained by placing a specimen in an electric field with harmonically changing strength reveals general regularities in the evolution of the domain walls of A 2 BX 4-group crystals. It is established that the domain structure affects the nonlinear polarization properties of our specimens. The dependence of the potential relief of ferroelectric ion motion in a harmonically changing electric field is plotted on the basis of the experimental results. 相似文献
9.
V. Ya. Shur D. V. Pelegov V. A. Shikhova D. K. Kuznetsov E. V. Nikolaeva E. L. Rumyantsev O. V. Yakutova T. Granzow 《Physics of the Solid State》2010,52(2):346-351
Optical visualization with simultaneous recording of the switching current was used for studying of domain structure evolution in single crystals relaxor ferroelectric strontium barium niobate (Sr0.61Ba0.39Nb2O6) doped by cerium (0.22 mol %) (SBN61:Ce). It was shown that the maze domain structures can be observed during polarization reversal due to local change of refractive index induced by formation of microscale domains with charged domain walls. It was proposed, that optical inhomogeneities occur in the switching regions, while the optical uniform areas correspond to regions where the switching either has not started yet or has already completed. The original mathematical treatment of the obtained images and switching currents has been used for quantitative characterization of the polarization reversal process. 相似文献
10.
A self-consistent method based on the interaction of a piezoelectric sphere with a piezoelectric medium that has anisotropic
elastic and dielectric properties is used to calculate the components of the tensor piezoelectric modulus of BaTiO3 ceramic in all three ferroelectric modifications. A comparison of the calculated and measured piezoelectric moduli shows
that at least 60–70% of the piezoelectric effect in BaTiO3 ceramic is caused by domain boundary movement throughout the entire ferroelectric region.
Fiz. Tverd. Tela (St. Petersburg) 41, 1080–1083 (June 1999) 相似文献
11.
The influence of Ni doping on the ferroelectric and dielectric properties have been examined in Sr0.61Ba0.39Nb2O6 (SBN:61) relaxor crystals. The dopants introduced into SBN:61 crystals promote the switching process by reducing the value
of threshold nucleation field, and thus coercive field. We present real-time studies of domain nucleation and growth processes
in doped SBN:61 by the nematic liquid crystal (NLC) decoration technique. The broad phase transition and low-frequency dielectric
dispersion that are exhibited by doped SBN:61 samples have a strong link to the configuration of the ferroelectrics microdomains,
which in turn is strongly determined by Ni ions concentration. 相似文献
12.
S. N. Ivanov A. V. Taranov E. N. Khazanov E. P. Smirnova 《Journal of Experimental and Theoretical Physics》1999,88(2):342-346
Phonon transport in ferroelectric ceramics and single crystals has been experimentally investigated. Our measurements indicate
that, in the temperature range 1.7–3.8 K studied, the effective phonon diffusion coefficient behaves as D
eff∞T
−5 in ferroelectrics with a broadened phase transition. This experimental dependence is in accord with the presence of a plateau
in the thermal conductivity of such materials. The scattering by domain walls in BaTiO3 single crystals has been identified, and our results are in quantitative agreement with calculations.
Zh. éksp. Teor. Fiz. 115, 624–631 (February 1999) 相似文献
13.
Václav Janovec 《Phase Transitions》2017,90(1):1-10
ABSTRACTAxial crystals have axial symmetry which keeps invariant straight line with a fixed point. Axial symmetry groups include 27 non-cubic crystallographic point groups and 5 limit groups describing symmetry of textures and liquid crystals. We show that, except for four cases, each axial symmetry belongs to one of five axial types: polar, chiral, pseudopolar (three basic axial types), directional (possessing none of characteristic properties of basic types) or rotational (exhibiting characteristic properties of all basic types). Each basic type can appear in two structurally different variants with the same symmetry. These variants can coexist and form a mesoscopic structure (antiparallel ferroelectric or chiral domain structure, mixture of enantiomers). We examine macroscopic properties of axial types and variants, and experimental accessivity of their characteristic features. 相似文献
14.
D. A. Kiselev T. S. Ilina M. D. Malinkovich O. N. Sergeeva N. N. Bolshakova E. M. Semenova Yu. V. Kuznetsova 《Physics of the Solid State》2018,60(4):738-742
This paper presents the results of the study of the domain structure of barium titanate crystals in a wide temperature range including the Curie point (TC) using the polarization-optical method in the reflected light and the force microscopy of the piezoelectric response. It is shown that a new a–c domain structure forms during cyclic heating of the crystal above TC and subsequent cooling to the ferroelectric phase. The role of uncompensated charges appeared on the crystal surface during the phase transition and their influence on the formation of the domain structure during cooling are discussed. 相似文献
15.
Single crystals of ferroelectric PbNb2O6 were grown employing a modification of the technique of Goodman. The results obtained on the domain structure were analysed
and compared with those reported on BaTiO3 and KNbO3. The domain structure observed here corresponds to the twinning on (110) plane of the unit cell reported by Francombe and
Lewis or the subcell reported by Labbe and others. The (001) planes were observed, as the crystal habit is such as to produce
(001) planes, and the cleavage plane is also (001). Also the analysis of the observations can be done easily under these conditions.
The domains observed are 90° domains with polar axis in (001) plane. Wedge shaped domains and spikes are present as in BaTiO3 and KNbO3. The twinning can occur also on
plane producing a domain line at 90° with that due to twinning on (110). This gives patterns of perpendicular lines similar
to those in KNbO3 and BaTiO3. Crystal structure considerations show that the domain structures with polarization in and out of the observed (001) plane
are not possible, and also were not observed. In this sense, it is a two dimensional ferroelectric. The studies showed a peculiar
grain structure in the crystals, and it can be explained on the basis of the growth habit of the crystal. The polarizing microscope
is particularly useful in analysing the domain structure along with the grain structure. 相似文献
16.
A theory is developed for the magnetic resonance line shape in disordered ferroelectric crystals. In a study of the random
fields responsible for inhomogeneous line broadening, nonlinear and spatial correlation effects are taken into account. It
is shown that homogeneous broadening depends on the temperature and on the magnitude and orientation of the external magnetic
field, as well as on the nonlinearity parameters of the ferroelectric material. The resonance line shape is calculated as
the envelope of homogeneously broadened Lorentzian spin packets. Analytic expressions for I
2(ω) and I
3(ω) are introduced to account for nonlinearity and correlation effects of second and third order, respectively. Calculations
are done for centrally symmetric crystals, as well as for those without a center of symmetry. It is shown that homogeneous
broadening is important near the line peak, while the wings are determined mainly by inhomogeneous broadening. Manifestations
of the predicted effects in the spectrum lines of disordered ferroelectric crystals are discussed.
Fiz. Tverd. Tela (St. Petersburg) 40, 340–347 (February 1998) 相似文献
17.
D. V. Roshchupkin D. V. Irzhak D. V. Punegov 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(2):184-187
The acoustic properties of lanthanum-gallium tantalate crystals and the polar properties of ferroelectric lithium niobate crystals have been investigated by high-resolution X-ray diffraction and topography. It is shown that analysis of the diffraction spectra of acoustically modulated crystals makes it possible to determine the acoustic amplitudes and power flow angles. It was also demonstrated that investigation of the domain structure in ferroelectric crystals under the conditions of the inverse piezoelectric effect allows one to study the domain structure. 相似文献
18.
19.
Effect of the sintering temperature on the formation of the microstructure, the domain structure, and the ferroelectric properties of a lead zirconate–titanate Pb(Ti x Zr1 – x)O3 piezoelectric ceramics has been studied. It is shown that the ferroelectric phase forms at a sintering temperature of 860°C. At higher sintering temperatures, the main effect on the properties is due to a unit cell deformation and free charge carriers. 相似文献
20.
The experimental results on ultrasonic stress wave interaction with domain walls in KD2PO4 crystals are presented. It is shown that the interaction takes place only if stress waves are piezoelectrically coupled to ferroelectric polarization. The temperature dependence of domain wall mobility is found. 相似文献