Showing papers by "Yoshihiro Ishibashi published in 1984"
TL;DR: In this article, the authors investigated nucleation and domain growth in the switching of DOBAMBC by means of sequential microscope photographs taken with pulsed light and by laser light transmission and found that the electric field dependences of the switching time, the domain wall velocity and the density of nuclei obey power laws.
Abstract: Nucleation and domain growth in the switching of DOBAMBC were investigated by means of sequential microscope photographs taken with pulsed light and by laser light transmission It was found that the electric field dependences of the switching time ts, the domain wall velocity v and the density of nuclei n obey power laws The essence of the switching behavior is described well by the Avrami formula
23 citations
TL;DR: The functional form of the thickness dependence of the pinning energy of kinks due to discreteness of substrate lattices is discussed by using the contour integral method in this article.
Abstract: The functional form of the thickness dependence of the pinning energy of kinks due to discreteness of substrate lattices is discussed by using the contour integral method. It is shown that the functional form can be guessed without knowing the energy distribution as a function of coordinate. The relative stability of the kinks of the odd and the even types may be sometimes reversed according to the parameter values describing the substrate potential. The result previously reported for a nonlinear deformable potential is interpreted. The contour integral method is applied to calculate the pinning energy of the double quadratic kinks.
20 citations
TL;DR: In this article, the structure, the formation and activation energies of a domain wall in crystals are discussed on the basis of analyses of a first order transition model in the close vicinity of the transition temperature, the domain wall is considerably extended.
Abstract: The structure, the formation and the activation energies of a domain wall in crystals are discussed on the basis of analyses of a first order transition model In the close vicinity of the transition temperature, the domain wall is considerably extended For the estimation of the activation energy of a thick domain wall the method of the contour integral was adopted It has turned out that the relative stability of an even and an odd walls varies with temperature
17 citations
TL;DR: In this article, the temperature dependences or the soft TO mode and the associated LO mode in Li 2 Ge 7 O 15 have been measured by Raman scattering technique in the ferroelectric phase.
Abstract: The temperature dependences or the soft TO mode and the associated LO mode in Li 2 Ge 7 O 15 have been measured by Raman scattering technique in the ferroelectric phase. The frequency of the LO mode decreases as T c is approached from below. The LO-TO splitting of the soft mode was observed to be smaller than 1 cm -1 . The results are discussed in the relationship with those obtained through measurements of dielectric constant. The oscillator strength for the polar soft mode in the paraelectric phase is expected to be very small.
9 citations
TL;DR: In this paper, an extension of the Slater theory of the ferroelectric phase transition in KH 2 PO 4 has been tried by introducing into it the terms of the second and fourth orders in an order parameter, i.e., the polarization, each representing the dipole interaction and the electrostriction.
Abstract: After detailed analyses of the Slater theory of the ferroelectric phase transition in KH 2 PO 4 , an extension of it has been tried by introducing into it the terms of the second and the fourth orders in an order parameter, i.e., the polarization, each representing the dipole interaction and the electrostriction. By constructing phase diagrams in the space of temperature and newly introduced parameters, the nature of the transition point derived from the Slater theory become more clearly understood, i.e., it is a triple point and at the same time can be regarded as an end point of the tricritical line.
6 citations
TL;DR: In this article, the authors investigated the transient processes of the field induced Sm C*-to-Sm C transition and the reverse Sm C-toSm C* transition by means of the sequential microscope photographs.
Abstract: The transient processes of the field induced Sm C*-to-Sm C transition and the reverse Sm C-to-Sm C* transition were investigated by means of the sequential microscope photographs. It has turned out that the two transition processes are different in mechanism. The former is similar to the switching in ferroelectrics in the sense that a domain structure is formed during the transition. As for the latter, the transition seems to occur homogeneously at all parts of specimens. A simple rate equation describing the latter process is presented.
6 citations
TL;DR: In this paper, dielectric and dilatometric measurements were carried out to study the intermediate incommensurate phase of quartz crystal, which is stabilized between the α- and the β-phases.
Abstract: Dielectric and dilatometric measurements were carried out to study the intermediate incommensurate phase of quartz crystal, which is stabilized between the α- and the β-phases. Anomalies associated with the transitions from the high temperature β-phase to the incommensurate phase and then to the α-phase were observed.
5 citations
TL;DR: In this article, the Peierls energy of a double sine-Gordon dislocation as a function of the position of the dislocation center is analytically estimated by means of the contour integral.
Abstract: The Peierls energy of a double sine-Gordon dislocation as a function of the position of the dislocation center is analytically estimated by means of the contour integral. It turns out that the relative stability of dislocation of the even-type and of the odd-type depends on a parameter a /4 b which determines the form of the substrate potential.
5 citations
TL;DR: In this paper, Clausius-Clapeyron and Ehrenfest relations were examined for improper ferroelectric and ferroelastic transition in the presence of an electric field.
Abstract: Phase diagrams in the applied electric field vs the temperature plane were studied for several cases of improper ferroelectric and ferroelastic transitions. An interesting phase diagram including a re-entrant phase and a tricritical point is obtained when the system undergoes the ferroelastic-ferroelectric transition in the absence of the electric field. The anomalies in the temperature dependence of transition parameters, the electric susceptibility and the elastic stiffness constant are discussed. The nature of transitions is examined from the viewpoint of the Clausius-Clapeyron and the Ehrenfest relations.
3 citations