“Local phase transitions” and related relaxation processes in incipient ferroelectrics with a perovskite-like structure

Vikhnin, V. S.; Трепаков, В. А.; Smutný, F.; Jastrabı́k, L.

doi:10.1080/00150199608223596

Cited by 20 publications

(13 citation statements)

References 18 publications

(4 reference statements)

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“…At ∼105 K it possesses a cubic-tetragonal structural phase transition O 1 h → D 18 4h . The luminescence of Mn 4+ impurity ions reveal very unusual properties of zerophonon emission line 2 E → 4 A 2 , which are associated with strong interaction with TO 1 mode and with instability of d 3 impurity ion in 2 E excited state with respect to TO 1 mode related polar distortions [1].…”

Section: Introductionmentioning

confidence: 99%

Application of Spectroscopic Probes in Study of Ferroelectrics

Bryknar

2004

Ferroelectrics

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A 2 ) and vibrational sidebands. It is suggested that unusually large temperature shift of ZPL is caused mainly by the contribution of the lowest TO soft optical branch into interaction of emitting center with a lattice. The PL spectrum of Cd 2 Nb 2 O 7 :Cr 3+ consists of four narrow emission lines accompanied by vibrational sidebands. Emission lines are attributed to the zero-phonon transitions 2 E → 4 A 2 of two kinds of octahedral coordinated Cr 3+ centers. The change in activation energies of PL thermal quenching at T c = 196 K is tentatively explained by a change of the adiabatic potential of the Cr 3+ centers at the ferroelectric phase transition of Cd 2 Nb 2 O 7 at T c . The low-temperature photosensitivity of both materials is attributed to the photoinduced change of charge state of manganese and chromium centers.

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Section: Introductionmentioning

confidence: 99%

Application of Spectroscopic Probes in Study of Ferroelectrics

Bryknar

2004

Ferroelectrics

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“…The observation of the Fano effect, and the suggestions based on it that local polar regions exist in STO thin films, may hold the key to the understanding of the lattice dynamical and dielectric properties of ferroelectric thin films. The existence of such local polar regions around defects or oxygen vacancies has been proposed in bulk materials both experimentally [27,28,44,56] and theoretically [57][58][59].…”

Section: Discussionmentioning

confidence: 98%

Lattice dynamical properties of SrTiO[sub 3] thin films

Sirenko¹,

Акимов²,

Bernhard³

et al. 2000

AIP Conference Proceedings

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We report the experimental studies of the vibrational spectra of SrTiO 3 films grown by pulsed laser deposition. Raman scattering, with and without bias electric field, and Fourier-transform far-infrared ellipsometry between 30 and 700 cm −1 have been utilized for investigation of the phonon behavior. These results are discussed in connection with the low-frequency dielectric properties of the SrTiO 3 films. In the films, the soft mode reveals hardening compared to that in bulk crystals. This observation is in agreement with the Lyddane-Sachs-Teller formalism. The existence of local polar regions is proposed as an important factor determining the dielectric properties of ferroelectric thin films.

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“…As it was recognized in, 7 the zero-phonon R emission line ( 2 E → 4 A 2 ) of octahedral Cr 3+ impurity center in SrTiO 3 shifts strongly to lower energies at cooling as ν ∼ 1/ε ∼ ω 2 0 , i.e., is controlled by TO1 mode 7,8 (more exactly -due to interaction of the optical centre with the local soft mode, whose behavior depends strongly on TO1 lattice mode). 9 Such Cr 3+ impurity spectroscopy method have been successfully used by us for the studies of KTaO 3 , Sr 1−x Ca x TiO 3 , and SrTiO 3 :Mg crystals and ceramics. [8][9][10][11][12] In this work we applied this strategy for SrTiO 3 sol-gel ceramics of average grain size ∼24 m.…”

Section: Introductionmentioning

confidence: 99%

“…9 Such Cr 3+ impurity spectroscopy method have been successfully used by us for the studies of KTaO 3 , Sr 1−x Ca x TiO 3 , and SrTiO 3 :Mg crystals and ceramics. [8][9][10][11][12] In this work we applied this strategy for SrTiO 3 sol-gel ceramics of average grain size ∼24 m.…”

Section: Introductionmentioning

confidence: 99%