Electroluminescence from Fe-doped BaTiO3

Aguilar, M.; Gonzalo, C.; Montoto, L.

doi:10.1080/00150198408012722

Cited by 2 publications

(3 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Strong exothermic peaks are observed in the temperature range of 200-400ºC, and are attributed to the burning of organic material. Atsuki et al [9] reported a similar exothermic behaviour in the preparation of SBN by a Pechini-type method. Exothermic features, in this temperature were also detected during the heating of SBN and SrBi 2 Ta 2 O 9 (SBT) precursor gels prepared by chemical synthesis [4,7,8] and were assigned to the burnout of organics.…”

Section: Resultsmentioning

confidence: 77%

“…According to the identified XRD patterns, it is suggested that the crystallization of strontium oxide may be related to the exothermic feature. Concerning the endothermic feature, Bi 2 O 3 melting may be assigned to the endothermic shoulder at ~830ºC [9] and the sharp peak at 880ºC is attributed to the carbonate decomposition, according to a DTA performed on the SrCO 3 reagent. Both phenomena promote the reaction of SBN precursors since SBN peaks become well identified at temperatures above 900ºC.…”

Section: Advanced Materials Forum IImentioning

confidence: 99%

See 1 more Smart Citation

Synthesis and Characterization of SrBi2Nb2O9 Powders Prepared by a New Chemical Method

Aguilar

Costa

2004

MSF

View full text Add to dashboard Cite

SrBi 2 Nb 2 O 9 (SBN) is a Bi-layered perovskite compound that, due to it relatively high Curie temperature, has potential application as high ceramic transducer. The preparation of SBN by the conventional solid state route requires high temperatures (above 1000ºC) which allow significant bismuth losses, leading to non-stoichiometric compositions. This work describes a new method to obtain SBN that overcomes this problem. Compared to sol-gel methods, it has the advantage of using reagents that are less toxic and less expensive than the alkoxides used by these chemical methods. The thermal behavior of SBN precursors prepared by this new method is compared to that observed by the conventional solid state route. This new method offers the possibility of producing SBN at lower temperatures than those needed by the conventional route.

show abstract

Section: Resultsmentioning

confidence: 77%

Section: Advanced Materials Forum IImentioning

confidence: 99%

Synthesis and Characterization of SrBi2Nb2O9 Powders Prepared by a New Chemical Method

Aguilar

Costa

2004

MSF

View full text Add to dashboard Cite

show abstract

“…For example, multielectron ferronic states in antiferromagnetic semiconductors are well known. The intensive electron emission 33,34 and luminescence [35][36][37] observed during ferroelectric switching are indicative of the existence of many electrons involved in the repolarization process. 32.…”

Section: Repolarization Nuclei As Fluctuonsmentioning

confidence: 99%

Fluctuon effects in ferroelectric polarization switching

Molotskii

Kris

Rosenman

2000

Journal of Applied Physics

View full text Add to dashboard Cite

The perplexing problem of the extremely large activation energy for nucleation U ac ϳ10 6 eV, which, as was shown by Landauer, appears in the Merz thermal-fluctuational theory of ferroelectric switching, is examined. Such enormous values of U ac are a result of the combined contribution of the energy of the depolarization field and the surface energy of the nucleus. While the depolarizing field term can be reduced by a redistribution of free charges, the surface energy term alone is too large ͑greater than 10 4 eV) for thermal-fluctuation-aided nucleation to be possible. This conclusion contradicts the numerous observations of a rapid increase in the number of repolarization nuclei with temperature, which suggest that the actual activation energy is on the order of an electron volt. This article is devoted to the problem of how the surface energy of a nucleus can be compensated. It is assumed that repolarization nuclei form by a fluctuon mechanism, and it is shown how this assumption can help in resolving the conflict between theory and experiment. It is suggested that upon application of an external electric field, electrons tunnel into the region where the spontaneous polarization vector fluctuates. This fluctuation region maintains its stability owing to the field of the electrons localized within the region. This leads to the appearance of a multielectron fluctuon, which is a bound state of electrons and a fluctuation and can be regarded as a repolarization nucleus. The electronic structure of these nuclei is calculated with density-functional theory. The calculations show that fluctuon effects can fully compensate the surface energy term. The assumption that repolarization nuclei have a fluctuon nature is shown to account for the principal laws governing the switching process, including low activation energy values. The results of possible experiments that could verify the proposed mechanism are predicted.

show abstract

Electroluminescence from Fe-doped BaTiO3

Cited by 2 publications

References 2 publications

Synthesis and Characterization of SrBi<sub>2</sub>Nb<sub>2</sub>O<sub>9</sub> Powders Prepared by a New Chemical Method

Synthesis and Characterization of SrBi<sub>2</sub>Nb<sub>2</sub>O<sub>9</sub> Powders Prepared by a New Chemical Method

Fluctuon effects in ferroelectric polarization switching

Contact Info

Product

Resources

About