The ferroelectric phase transition of calcium barium niobate: experimental evidence of Smolenskii's model for diffuse phase transitions?

Heine, Urs; Voelker, Uwe; Betzler, K.; Burianek, Manfred; Muehlberg, Manfred

doi:10.1088/1367-2630/11/8/083021

Cited by 9 publications

(8 citation statements)

References 19 publications

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“…1. Failure of the dielectric behavior above T m to collapse to a single frequency-independent curve could be simply due to sampling in a small temperature window, or due 21 to space charge associated with low crystallinity, or due [21][22][23] to inhomogeneity such that the transition is smeared out. The discrepancy in the absolute value of the calculated permittivity at 1 kHz ͑ϳ5%͒ ͑between Fig.…”

mentioning

confidence: 99%

Investigation of the electrocaloric effect in a PbMg2/3Nb1/3O3-PbTiO3 relaxor thin film

Correia¹,

Young²,

Whatmore³

et al. 2009

Applied Physics Letters

204

103

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confidence: 99%

Investigation of the electrocaloric effect in a PbMg2/3Nb1/3O3-PbTiO3 relaxor thin film

Correia¹,

Young²,

Whatmore³

et al. 2009

Applied Physics Letters

204

103

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“…Calcium barium niobate, Ca x Ba 1−x Nb 2 O 6 (CBN), compounds also have TTB structures, and their physical properties are very similar to those of SBN, whereas their Curie temperatures T C exceed those of SBN [16][17][18][19]. Due to the smaller ionic radius of Ca 2+ compared to that of Sr 2+ , most of the Ca ions occupy A1 sites, whereas most of the Ba ions occupy A2 sites.…”

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confidence: 99%

Critical slowing down and elastic anomaly of uniaxial ferroelectricCa0.28Ba0.72Nb2O6crystals with tungsten bronze structure

et al. 2014

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The ferroelectric phase transition of uniaxial Ca 0.28 Ba 0.72 Nb 2 O 6 single crystals with a moderate effective charge disorder was investigated by Brillouin scattering to clarify the dynamic properties. In the tetragonal paraelectric phase a remarkable softening of the sound velocity of the longitudinal acoustic mode and a significant increase in the sound attenuation were observed close to the Curie temperature T C = 527 K. The intermediate temperature T * ∼ 640 K and the Burns temperature T B ∼ 790 K were determined from the temperature variation in the sound attenuation. The intense broad central peak (CP) caused by polarization and strain fluctuations due to polar nanoregions was clearly observed in the vicinity of T C . The relaxation time determined by the CP width clearly shows critical slowing down towards T C , reflecting a weakly first-order phase transition under weak random fields.

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“…Seemingly, in the case of CBN, the effect of the random fields is much weaker. Indeed, in CBN Ca 2+ ions are restricted to the square A1 sites, whereas the pentagonal A2 sites are nearly fully occupied by Ba 2+ exclusively [14]. In contrast, in SBN, Sr 2+ is equally distributed between A1 and A2; additionally, A2 is less than 50% occupied by barium.…”

Section: Resultsmentioning

confidence: 99%

“…These methods, however, are destructive and allow for observation of static patterns only. Non-destructive but indirect investigations of the evolution of domain structures in the vicinity of the Curie temperature of CBN28 were performed via second harmonic generation k -space spectroscopy [14]. A nonuniformity of the ferroelectric phase transition for differently sized polar structures was revealed, which resembles the diffuse phase transition model proposed by Smolenskii [15].…”

Section: Introductionmentioning

confidence: 99%

A Piezoresponse Force Microscopy Study of CaxBa1−xNb2O6 Single Crystals

2017

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Polar structures of Ca x Ba 1−x Nb 2 O 6 (CBN100x) single crystals were investigated using piezoresponse force microscopy. Increasing Ca content results in decreasing domain size and enhancement of the polar disorder. For the composition with x = 0.32 the characteristic domain size is similar to that reported for relaxor Sr 0.61 Ba 0.39 Nb 2 O 6 (SBN61). However, decay of an artificial macroscopic domain in CBN32 takes place below the macroscopic transition temperature, contrary to SBN61, where random fields stabilize it above the transition temperature. We can conclude that CBN with 0.26 ≤ x ≤ 0.32 does not display classical relaxor behavior and might be considered as a disordered ferroelectric.

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The ferroelectric phase transition of calcium barium niobate: experimental evidence of Smolenskii's model for diffuse phase transitions?

Cited by 9 publications

References 19 publications

Investigation of the electrocaloric effect in a PbMg2/3Nb1/3O3-PbTiO3 relaxor thin film

Investigation of the electrocaloric effect in a PbMg2/3Nb1/3O3-PbTiO3 relaxor thin film

Critical slowing down and elastic anomaly of uniaxial ferroelectricCa0.28Ba0.72Nb2O6crystals with tungsten bronze structure

A Piezoresponse Force Microscopy Study of CaxBa1−xNb2O6 Single Crystals

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