A. L. Subbotin

DOMAIN STRUCTURE OF LEAD GERMANATE

With the help of selective etchants as-grown domain structure arising as a result of the phase transition and its restruction in electric field is investigated in lead germanate single crystals. It is shown that this structure consists of small counter domains which are enlarged in electric field. By the use of stroboscopic lighting the domain dynamics under applied electric field is studied. It is shown that the influence of growth layers upon forward domain growth can be explained by the relative variation of the spontaneous polarization in the layers of the order of 0,1%. The observed peculiarities of sidewise motion of plane domain wall are explained by the presence of dielectric gap and by the influence of bulk screening. It is supposed that in low-field region domain wall motion occurs through the one-dimensional nucleation at the wall. Within this model it is possible to qualitatively explain the domain shape dependence on the switching conditions.

Transient current during switching in increasing electric field as a basis for a new testing method

Abstract The paper presents the new method of detail analyzing of transient current data in linear increasing electric field, which allows to obtain the time dependence of main parameters characterizing the domain kinetics. The switching process in PZT thin films, so as in Pb5Ge3O11 model single crystal was investigated.

Elastic light scattering as a probe for detail in situ investigations of domain and phase evolution

Abstract The new complex method is proposed and used for in situ studying of kinetics of different phase transformations. It is based on real-time registration of elastic light scattering and original mathematical treatment of experimental data in terms of geometrical transformations and phase transitions of percolation type. The angle distribution of transmitted/reflected laser beam intensity was registered with high time resolution. The domain kinetics during polarization reversal in PLZT transparent ceramics, the evolution of the heterophase structure near transition point in single crystals of Gd2(MoO4)3 and kinetics of crystallite growth during rapid thermal annealing in amorphous thin films of Pb5Ge3O11 were examined.

Influence of crystallization kinetics on texture of sol–gel PZT and BST thin films

Abstract The evolution of morphology of sol–gel PZT and BST thin films during rapid thermal annealing (RTA) is investigated by recording of elastic light scattering data in reflected mode. The analysis of film morphology and texture evolution obtained by XRD reveals the dependence of crystallization kinetics on the annealing conditions. The evolution of film morphology during the transition to the perovskite phase is analysed by the time dependence of fractal dimensionality. The parameters characterizing the kinetics of the transformation to the perovskite phase are extracted by mathematical treatment of experimental data. A mechanism for texture formation is proposed.

Forming of the domain structure in lead germanate during phase transition

Abstract The results of the observation of as-grown domain structure in lead germanate Pb5Ge3O11 (LGO) by specially deviced cleavage method are presented. The influence of periodic composition inhomogeneties (growth layers) is investigated. It is shown that the observed at room temperature frozen-in domain pattern is defined by the orientation of growth layers relative to the polar axis and selfreconstruction of domain distribution during cooling.

Smooth and jump-like dynamics of the plane domain wall in gadolinium molybdate

Abstract The paper deals with the detail investigation of the smooth motion of the single plane domain wall (PDW) in the vicinity of the initial/steady position and analysis of the mechanisms of Barkhausen noise generation during PDW jump-like motion.

Motion of a planar domain wall in the ferroelectric-ferroelastic gadolinium molybdate

The lateral motion of a planar domain wall (PDW) in an electric field and the spontaneous rotation of the wall in the initial position after the field is switched off were investigated in the improper ferroelectric-ferroelastic gadolinium molybdate Gd2(MoO4)3, using optical visualization and measurement of the switching currents. The characteristic behavior found for the PDW is attributed to the delay of the volume screening of the depolarizing fields. It is shown that the dependence of the motion of the PDW on the switching duration in an ac field is due to the redistribution of the screening charges.

Crystallization kinetics of amorphous ferroelectric films

Abstract The kinetic parameters characterizing the crystallite growth during annealing of PZT and PGO amorphous films were determined by proposed mathematical treatment of in situ elastic light scattering data.

Investigation of domain structure in lead germanate by cleavage method

Abstract The cleavage method is developed for investigation of the domain structure in lead germanate in samples with simple domain structure. It is verified that cleavage process does not alter domain structure and the observed pattern corresponds to domain pattern at the moment of cleavage. The observed phenomena is viewed as a result of crack growth in anisotropic medium. The method proves to be very useful for investigation of as-grown domain structure consisting of small nonthrough domains.

In Situ Investigation of Crystallization Kinetics in Pzt Films by Light Scattering

This paper presents the in situ investigation of the crystallite evolution/growth during annealing of amorphous sol-gel Pb(Zr,Ti)O 3 thin films by elastic light scattering. XRD and SEM measurements of partly crystallized films of crystallite evolution were used for verifying the method.