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The aim of doctoral dissertation „Grain Size Effect on Dielectric Properties of Ferroelectrics and Relaxors“ by Maksim Ivanov is to investigate, how grain size of ceramics and powders of a few ferroelectrics and relaxors influences macroscopic dielectric properties. The studied materials are powders of a relaxor PbMg⅓Nb⅔O3 (PMN), ceramics of a relaxor with a spontaneous phase transition PbSc½Nb½O3 (PSN), ceramics of a ferroelectric 0.36BiScO3-0.64PbTiO3, and ceramics of Ba2SnO4, which were compared to a better investigated BaSnO3. Investigations were performed in broad frequency (100 Hz – 55 GHz) and temperature (30 K – 1000 K) ranges. Experimental investigations and modelling showed, that bulk properties of relaxor materials are heavily influenced by polar nanoregions, but they do not fully determine them. Morphology of the material (i.e. grain size of ceramics) determines growth and interactions of the nanoregions, thus influencing bulk properties. Moreover, effective medium approximation can explain evolution of dielectric properties of ferroelectrics and relaxors only if dependence of bulk properties on grain size is known. The most interesting result is, that there exist polar entities in ferroelectrics, which are different from ferroelectric domains and are similar to polar nanoregions in relaxors. Their contribution to dielectric permittivity can be comparable to all other contributions. Dimensions of these entities depend on grain size in accordance with Kittel's law. / Maksimo Ivanovo daktaro disertacijos tema yra “Grūdų dydžio įtaka dielektrinėms feroelektrikų ir relaksorių savybėms”. Šio darbo tikslas yra ištirti, kaip keramikų ar miltelių grūdų dydis įtakoja makroskopiškai stebimas kelių feroelektrikų bei feroelektrinių relaksorių dielektrines savybes. Tirtos medžiagos yra klasikinio relaksoriuas PbMg⅓Nb⅔O3 (PMN) milteliai, relaksoriaus su savaiminiu feroelektriniu faziniu virsmu PbSc½Nb½O3 (PSN) keramikos, feroelektriko 0.36BiScO3-0.64PbTiO3 keramikos, bei Ba2SnO4 keramiką, kuri buvo palyginta su kiek labiau žinoma BaSnO3 keramika. Tyrimai buvo atlikti plačiame dažnių (100 Hz – 55 GHz) bei temperatūrų (30 K – 1000 K) intervaluose. Eksperimentiniai tyrimai bei modeliavimai parodė, kad polinės nanosritys labai stipriai įtakoja tūrines relaksorių savybes, tačiau jų neapsprendžia. Medžiagos morfologija (antai keramikų grūdų dydis) lemia nanosričių augimą bei tarpusavio sąveikas, tokiu būdų įtakojamos tūrinės savybės. Be to, efektyvios terpės aproksimacija gali paaiškinti feroelektrikų ir relaksorių dielektrinių savybių priklausomybę nuo grūdų dydžio tik, jei žinomas sąryšis tarp dydžio ir tūrinių savybių. Įdomiausia yra tai, kad feroelektrikuose yra objektų, kurie nėra feroelektriniai domenai ir yra panašūs į relaksorių polines nanosritis. Jų indėlis į dielektrinę skvarbą gali būti palyginamas su visų kitų procesų (pvz. domenų sienelių ir polinių modų) indėliais. Šių objektų dydis priklauso nuo grūdų dydžio pagal Kittel'io dėsnį.

Maksimo Ivanovo daktaro disertacijos tema yra “Grūdų dydžio įtaka dielektrinėms feroelektrikų ir relaksorių savybėms”. Šio darbo tikslas yra ištirti, kaip keramikų ar miltelių grūdų dydis įtakoja makroskopiškai stebimas kelių feroelektrikų bei feroelektrinių relaksorių dielektrines savybes. Tirtos medžiagos yra klasikinio relaksoriuas PbMg⅓Nb⅔O3 (PMN) milteliai, relaksoriaus su savaiminiu feroelektriniu faziniu virsmu PbSc½Nb½O3 (PSN) keramikos, feroelektriko 0.36BiScO3-0.64PbTiO3 keramikos, bei Ba2SnO4 keramiką, kuri buvo palyginta su kiek labiau žinoma BaSnO3 keramika. Tyrimai buvo atlikti plačiame dažnių (100 Hz – 55 GHz) bei temperatūrų (30 K – 1000 K) intervaluose. Eksperimentiniai tyrimai bei modeliavimai parodė, kad polinės nanosritys labai stipriai įtakoja tūrines relaksorių savybes, tačiau jų neapsprendžia. Medžiagos morfologija (antai keramikų grūdų dydis) lemia nanosričių augimą bei tarpusavio sąveikas, tokiu būdų įtakojamos tūrinės savybės. Be to, efektyvios terpės aproksimacija gali paaiškinti feroelektrikų ir relaksorių dielektrinių savybių priklausomybę nuo grūdų dydžio tik, jei žinomas sąryšis tarp dydžio ir tūrinių savybių. Įdomiausia yra tai, kad feroelektrikuose yra objektų, kurie nėra feroelektriniai domenai ir yra panašūs į relaksorių polines nanosritis. Jų indėlis į dielektrinę skvarbą gali būti palyginamas su visų kitų procesų (pvz. domenų sienelių ir polinių modų) indėliais. Šių objektų dydis priklauso nuo grūdų dydžio pagal Kittel'io dėsnį. / The aim of doctoral dissertation „Grain Size Effect on Dielectric Properties of Ferroelectrics and Relaxors“ by Maksim Ivanov is to investigate, how grain size of ceramics and powders of a few ferroelectrics and relaxors influences macroscopic dielectric properties. The studied materials are powders of a relaxor PbMg⅓Nb⅔O3 (PMN), ceramics of a relaxor with a spontaneous phase transition PbSc½Nb½O3 (PSN), ceramics of a ferroelectric 0.36BiScO3-0.64PbTiO3, and ceramics of Ba2SnO4, which were compared to a better investigated BaSnO3. Investigations were performed in broad frequency (100 Hz – 55 GHz) and temperature (30 K – 1000 K) ranges. Experimental investigations and modelling showed, that bulk properties of relaxor materials are heavily influenced by polar nanoregions, but they do not fully determine them. Morphology of the material (i.e. grain size of ceramics) determines growth and interactions of the nanoregions, thus influencing bulk properties. Moreover, effective medium approximation can explain evolution of dielectric properties of ferroelectrics and relaxors only if dependence of bulk properties on grain size is known. The most interesting result is, that there exist polar entities in ferroelectrics, which are different from ferroelectric domains and are similar to polar nanoregions in relaxors. Their contribution to dielectric permittivity can be comparable to all other contributions. Dimensions of these entities depend on grain size in accordance with Kittel's law.

Morphotrope PZT-Keramiken sind Festkörperlösungen aus Bleizirkonat und Bleititanat mit chemischen Zusammensetzungen um die 47% Ti-Anteil. Sie weisen im gepolten Zustand die größten piezoelektrischen Koppelkonstanten auf und sind daher von speziellem Interesse. Zur Vorhersage des Polungszustandes und der Bauteilfestigkeit in komplexen Bauteilen werden elektromechanisch gekoppelte Materialmodelle benötigt. In dieser Arbeit wird ein mikromechanischer Modellansatz aus der Literatur aufgegriffen. Ausgangspunkt ist ein dreidimensionales tetragonales Modell, welches ein repräsentatives Volumenelement des Kornverbundes und ein mikroskopisches Kornmodell vereint. Damit gelingt die Beschreibung der Korninteraktionen infolge unterschiedlicher Polungszustände der Körner. Die Domänenstruktur der Körner wird mittels der Volumenanteile der kristallographischen Varianten dargestellt. Ein vereinfachter Satz an mikroskopischen Materialkonstanten wird anhand experimenteller Daten und theoretischer Betrachtungen aus der Literatur abgeleitet. Die für zwei Lastfälle berechneten makroskopischen Materialantworten zeigen explizit, dass das tetragonale Modell nicht in der Lage ist, das Verhalten morphotroper PZT-Keramiken nachzubilden. Aus diesem Grund wird das Modell im Hinblick auf die besondere kristallographische Struktur morphotroper PZT-Keramiken um eine rhomboedrische Phase in veränderlichen Anteilen erweitert. Die somit berechneten makroskopischen Antworten stimmen sowohl quantitativ als auch qualitativ gut mit experimentellen Ergebnissen überein. Der Einfluss der im Modell berücksichtigten Kristallstruktur auf die makroskopische Materialantwort wird in der Arbeit ausführlich analysiert. / Morphotropic PZT ceramics are solid solutions made of lead zirconate and lead titanate with chemical composition around 47% Ti-content. When poled they possess the greatest piezoelectric coupling constants for which they are of special interest. Predicting the poling condition and the strength in complex devices requires electromechanically coupled material models. Within this work, a micromechanical modelling approach is utilised. Starting point is a three-dimensional tetragonal model, which combines a representative volume element of the grain compound together with a microscopic grain model. This allows the consideration of grain interaction due to different poling conditions of the grains. The domain structure of the grains is captured by volume fractions of the crystallographic variants. A simplified set of microscopic material constants is derived from experimental and theoretical data given in the literature. The macroscopic material response, which is computed for two load cases, shows explicitly that the tetragonal model is not capable of reproducing the behaviour of morphotropic PZT ceramics. Therefore, the model is extended by the rhombohedral phase in varying quantity with view of the specific crystallographic structure of morphotropic PZT ceramics. The so computed macroscopic response shows a quantitatively as well as qualitatively good agreement with experimental results. The effect of the crystallographic structure which is considered within the model on the macroscopic material response is extensively analysed.

Thesis (M.S.)--University of Alabama at Birmingham, 2008. / Description based on contents viewed May 30, 2008; title from title screen. Includes bibliographical references (p. 50-51).

Cette thèse s’intéresse à la conception de nouveaux matériaux compositesferroélectriques/diélectriques aux propriétés accordables en tension. Des granules diélectriques(MgO, TiO2) obtenues par atomisation sont dispersées dans une matrice ferroélectrique (Ba1-xSrxTiO3). Le mélange est ensuite densifié par Spark Plasma Sintering (SPS). Une approcheoriginale est développée afin de déterminer les paramètres reliant la microstructure aux propriétésphysiques pour chacune des étapes de la boucle d’optimisation élaboration - caractérisation -modélisation. La stratégie adoptée s’appuie sur i) l’utilisation des propriétés spécifiques du frittageSPS qui offre une gestion précise des interfaces entre les différents composés. Cette méthode nonconventionnellea permis l’élaboration de composites ferroélectriques architecturés, constituésd’inclusions diélectriques de géométries contrôlées ; ii) les potentialités offertes par lamicrotomographie X comme moyen de description de la microstructure 3D des matériauxcomposites aux étapes clés de leur conception. Couplée à de puissants outils de traitements desimages elle permet d’extraire les éléments pertinents guidant l’optimisation et la compréhension despropriétés finales ; iii) le développement d’un modèle numérique 3D de l’accordabilité appliquédirectement à la géométrie réelle des matériaux extraite des images de microtomographie. Cetteétape est essentielle pour comprendre l’origine de la redistribution du champ électrique entre lesphases. Les résultats numériques obtenus sont directement confrontés aux mesuresexpérimentales. / This thesis is focused on the conception of new tunable ferroelectric/dielectric compositematerials. Dielectric granules (MgO, TiO2) obtained by spray-drying are dispersed in a ferroelectricmatrix (Ba1-xSrxTiO3). Mixing powder is then densified by Spark Plasma Sintering (SPS). An originalapproach is developed in order to determine parameters linking the microstructure to the physicalproperties for each step of the elaboration - characterization - modelling optimization procedure.The adopted strategy is based on i) specific SPS properties which provide an accurate control of theinterfaces between each components; ii) potentialities offered by X-ray microtomography to describethe internal 3D microstructure of the composite materials during the key steps of their elaboration.Associated with powerful image processing tools, it allows to obtain relevant elements guiding theoptimization and understanding of the final properties; iii) the development of a 3D numerical modelof tunability applied directly to the real geometry which has been extracted from 3Dmicrotomography images. This step is essential to understand the origin of the redistribution of theelectric field between the different phases. Numerical results are directly compared to experimentalmeasurements.

Cette thèse vise à trouver des approches possibles pour l’amélioration des propriétés électromécaniques de monocristaux piézoélectriques à base de KNN. La TSSG et la SSSG sont entreprises afin de faire croître des monocristaux La conclusion de l'aspect de croissance cristalline est: (1) Pour chaque élément pris individuellement, leurs coefficients de ségrégation reposent fortement sur leurs concentrations initiales dans la solution liquide. (2) La compétition entre éléments occupant le même site du réseau est démontrée. (3) Le très faible coefficient de ségrégation de Li dans la matrice KNN est responsable de l'apparition d'une phase secondaire présentant la structure bronze de tungstène quadratique. (4) Les régions optiquement laiteuses observées dans les monocristaux diminuent la réponse électrique et peuvent être réduites par traitement thermique et refroidissement lent. Dans la deuxième partie, nous avons utilisé trois approches pour améliorer le comportement piézo/ferroélectrique des monocristaux à base de KNN. La Ta ou Sb substitution indique qu'une réponse électromécanique améliorée est obtenue lorsque la transition orthorhombique-quadratique est à proximité de la température ambiante. Le traitement thermique sous atmosphère d'O2 pur a conduit au doublement de la valeur du coefficient piézoélectrique et des paramètres ferroélectriques d'un monocristal de (K,Na,Li) (Ta,Nb,Sb)O3. Son coefficient piézoélectrique à la température ambiante, qui constitue un record mondial à l’heure actuelle vis-à-vis de ce qui est reporté dans la littérature internationale, vaut 732 pC/N. La troisième approche consiste au dopage des monocristaux de (K,Na,Li)(Ta,Nb)O3 avec Mn. / The thesis aims to find possible approaches for improved electromechanical properties in KNN-based piezoelectric single crystals. Both submerged-seed and top-seeded solution growth techniques were employed to produce single crystals. Conclusions from the crystal growth aspect are: (i) For individual elements, segregation coefficients highly rely on the initial concentration in the liquid solution. (ii) A competition between elements occupied on the same lattice site was found. (iii) The very low Li segregation coefficient in the KNN matrix is responsible for the occurrence of a secondary phase with the tetragonal tungsten bronze structure. (iv) Observed optically-cloudy regions in as-grown crystals decrease the electrical response and can be reduced by thermal treatment with slow cooling. In the second part, we used three approaches to enhance the piezoelectric and ferroelectric behavior of KNN-based single crystals. Ta or Sb substitutions indicates that enhanced electromechanical response is achieved when the orthorhombic-tetragonal phase transition is near room temperature. Thermal treatment in pure O2 atmosphere resulted in a twofold increase of the piezoelectric coefficient and ferroelectric parameters of a (K,Na,Li)(Ta,Nb,Sb)O3 single crystal. The highest room-temperature piezoelectric coefficient in annealed KNN-based single crystals of 732 pC/N was obtained. The third approach, doping with Mn ions in (K,Na,Li)(Ta,Nb)O3 single crystals, is also presented.

Orientador: José de los Santos Guerra / Resumo: O titanato de bário (BaTiO3, BT) é um material ferroelétrico com diversas aplicações, dentro do mercado de componentes eletrônicos, devido às excelentes propriedades físicas que manifesta, em relação a outros sistemas ferroelétricos, continuando a atrair durante várias décadas o interesse científico e comercial. Dentre o grande número de trabalhos sobre o sistema BT reportados na literatura muitos são associados à vasta gama de aplicações para a indústria eletro-eletrônica, dentre as quais se destacam o uso em dispositivos para capacitores, termistores, entre outros. A dopagem do BaTiO3 com íons doadores implica na mudança de algumas propriedades físicas, que conduzem a comportamentos anómalos em determinados parâmetros físicos, cuja natureza ainda não tem sido muito esclarecida, embora muitos trabalhos tenham se empenhado para tentar justificar tais efeitos. Neste contexto, neste trabalho, as propriedades físicas do sistema BaTiO3 serão investigadas considerando a adição de elementos doadores, nos sítios A e B da estrutura. Em particular, os íons de gadolínio (Gd3+) e nióbio (Nb5+) serão usados como modificadores da estrutura perovskita em substituição dos íons de bário (Ba2+) e titânio (Ti4+) nos sítios A e B, respectivamente, considerando as fórmulas químicas Ba1-xGdxTiO3 e BaTi1-x NbxO3 (sendo x = 0.001, 0.002, 0.003, 0.004 e 0.005). As propriedades estruturais e microestruturais foram investigadas à temperatura ambiente, enquanto as propriedades dielétricas e elétricas f... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Les solutions solides appartenant au système quasi-ternaire BaTiO3-CaTiO3-BaZrO3 (BCTZ) sont des candidates prometteuses pour les piézoélectriques sans plomb. Ce travail de thèse expérimental est consacré à la cristallogenèse et à la caractérisation de différents monocristaux dans le système BCTZ : BaZrO3, CaTiO3 ainsi que les solutions solides Ba1-xCaxTi1-yZryO3 présentant des teneurs en zirconium (Zr) et en calcium (Ca) proches de celles de la composition Ba(Zr0.2Ti0.8)O3-50(Ba0.7Ca0.3)TiO3 (BZT-50BCT) où les performances piézoélectriques sont exacerbées.Les monocristaux de CaTiO3 et de BaZrO3 ont été obtenus à la fois depuis une solution à haute température par la méthode du flux et à partir de leur phase fondue par la technique de la zone flottante optique. Dans le cas de CaTiO3 obtenu dans un four à image à 1975°C, l'aluminium (Al), le magnésium (Mg) et le baryum (Ba) ont été détectés comme étant les principales impuretés. Les spectres Raman de CaTiO3 sont en bon accord avec les spectres référencés dans la littérature. La croissance cristalline de BaZrO3 est beaucoup plus difficile à cause de son point de fusion très élevé (2700°C). Le flux BaB2O4 a été utilisé avec succès pour faire croitre des cristaux d’environ 150-200μm à 1350°C, soit à la moitié de son point de fusion. Des boules de BaZrO3 de taille centimétrique ont également été obtenues à partir de la phase fondue en four à image. Les impuretés majoritaires telles le strontium (Sr), l’hafnium (Hf), le calcium (Ca) et le titane (Ti) ont été détectées par GDMS et SIMS dans une gamme de concertation atomique de 0.3-0.5%. L’énergie de gap optique est d'environ 4,8 eV et souligne la grande qualité des cristaux de BaZrO3 obtenus en four à image. Les propriétés diélectriques à basse température de BaZrO3 confirment l'absence de transition de phase structurelle. Les études de Raman révèlent que même si BaZrO3 n'a pas de transition de phase à basse température, il présente une transition de phase cubique-quadratique sous haute pression à 11GPa à température ambiante.Dans la deuxième partie de cette thèse, des monocristaux centimétriques de BCTZ ont été obtenus avec succès par la croissance en flux. Les profils de concentrations en Ca et Zr le long des boules indiquent que leurs coefficients effectifs de ségrégation dépendent fortement de leur concentration initiale dans la solution liquide. Ceux-ci évoluent considérablement au cours du processus de cristallogenèse, rendant ainsi la croissance de BCTZ très délicate en vue d’obtenir des compositions constantes et proches de celles de la région de convergence de phases. De plus, une décomposition spinodale a été mise en évidence, indiquant la coexistence de deux solutions solides de compositions proches au sein des cristaux de BCTZ. Les propriétés diélectriques et piézoélectriques des cristaux obtenus ont été déterminées et présentent des caractéristiques allant du ferroélectrique classique au relaxeur. Les mesures diélectriques montrent notamment une double boucle d'hystérésis (PE) anormale qui disparaît après polarisation. / Solid solutions belonging to BaZrO3–BaTiO3–CaTiO3 (BCTZ) pseudo-ternary system are promising candidates for lead-free piezoelectrics. This thesis aims at growing and characterizing various single crystals of the BCTZ system: the end members BaZrO3 and CaTiO3 as well as Ba1-xCaxTi1-yZryO3 solid solution compounds with zirconium (Zr) and calcium (Ca) contents close to Ba(Zr0.2Ti0.8)O3-50(Ba0.7Ca0.3)TiO3 composition (BZT-50BCT) where high piezoelectric performances are expected.CaTiO3 and BaZrO3 single crystals were both grown from high temperature solution by the flux method and from the melt by the optical floating zone technique. In the case of CaTiO3 grown with a mirror furnace at 1975°C, aluminum (Al), magnesium (Mg) and barium (Ba) as main impurities were detected. The Raman spectra of CaTiO3 are in good agreement with the spectra referenced in the literature. The growth of BaZrO3 was more challenging because of its very high melting point (2700°C). BaB2O4 flux was successfully used to produce 150-200 μm-sized BaZrO3 crystals at half its melting point (1350°C) and bulk centimeter-sized BaZrO3 boules were grown from the melt. Sr, Hf, Ca and Ti were detected by GDMS and SIMS as main impurities in the range of 0.3-0.5 at.%. The optical band gap is found to be ~4.8 eV and indicates the high quality of the BaZrO3 crystals grown with mirror furnace. Low temperature dielectric properties of BaZrO3 are displayed and confirmed the absence of structural phase transition. Raman investigations reveal that even though BaZrO3 does not have any phase transition at low temperatures, it exhibits a high-pressure phase transition from cubic to tetragonal at 11GPa at room temperature.In the second part, BCTZ centimeter-sized single crystals have been successfully grown by the top seeded solution growth technique. Ca and Zr content profiles throughout the as-grown boules indicate that their effective segregation coefficients are highly dependent on their initial concentration in the liquid solution. Concentrations evolve substantially during the crystal growth, making the BCTZ crystal growth a tricky issue when a narrow compositions range is targeted, as in the vicinity of the phase convergence region. Furthermore, spinodal decomposition was observed, indicating the coexistence of two solid solutions with close compositions in BCTZ crystals. Dielectric and piezoelectric properties were measured for some crystals, which were found to display a variety of behavior form relaxor to pure ferroelectric. In addition, an abnormal double-like PE hysteresis loop was observed, that was associated to an irreversible effect disappearing upon poling.

CAMPOS FILHO, Múcio Costa. Estudo das propriedades dielétricas e ópticas na matriz cerâmica CaBi4Ti4O15 com adição de V2O5, Er2O3 e Yb2O3. 2015. 169 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2015. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-10-26T21:58:54Z No. of bitstreams: 1 2015_tese_mccamposfilho.pdf: 9304166 bytes, checksum: 0448bdd2063e3fc697dee9f5c6efb532 (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-10-26T21:59:04Z (GMT) No. of bitstreams: 1 2015_tese_mccamposfilho.pdf: 9304166 bytes, checksum: 0448bdd2063e3fc697dee9f5c6efb532 (MD5) / Made available in DSpace on 2015-10-26T21:59:04Z (GMT). No. of bitstreams: 1 2015_tese_mccamposfilho.pdf: 9304166 bytes, checksum: 0448bdd2063e3fc697dee9f5c6efb532 (MD5) Previous issue date: 2015 / A strong demand for compressed materials, low cost and easy to manufacture are needed for various technological applications, in this sense many ceramics are candidates for its dielectric and optical properties .In this work, structural, dielectric and optical phase of the orthorhombic ferroelectric ceramic matrixCaBi4Ti4O15were investigated, one pseudo-perovskite bismuth layer structure (BLSFs) of space group A21am of the aurivillius family, prepared by the solid state method and sintered in low temperatures. Sample preparation for structural analysis and dielectric, had the addition of vanadium pentóxido (V2O5) to the phase CaBi4Ti4O15 calcined in ratios of 0.5, 1.0, 1.5, 2.0 and 5.0% by mass. To obtain optical properties of the ceramic matrix doped with rare earth ions erbiumIII (Er2O3) and III ytterbium oxide (Yb2O3). The study of the structure and composition of the samples was done by X-ray diffraction and confirmation was made by single stage rietveld refinement. The vibrational characteristics was obtained by Raman spectroscopy (RS). The morphology study off or analysis of grain and grain boundary, was performed by scanning electron microscopy. The dielectric characterization of radio frequency spectroscopy was performed in impedance which occurred two conductivity mechanisms for all samples, one at low frequency and the on the rat high frequency. Models of dielectric relaxation approach the Cole-Cole type model. Measures in the microwave range were obtained using the hakki-coleman method and monopole, which gave a temperature coefficient of resonant frequency (f) close to zero with the addition of V2O5. The dielectric permittivity measurements in radiofrequency and microwave, performe dat room temperature, had a high constant value (εr≈150) with the addition of 1%V2O5, and a value of relatively low loss tangent for family aurivillus (tan[δ]≈10-2) at 2 GHz. A numerical simulation was performed with each sample verifying approach with the experimental data. In rare earth doped samples was checked energy up-conversion phenomenon with the presence of intense bands samples of visible light emission in the green region and a less intense bands in thered region.The investigated material has potential for application in volatile memories, capacitive filters and optical components such as sensors, solar cells and LEDs. / Uma forte demanda por materiais mais compactados, de baixo custo e de fácil fabricação são necessários para diversas aplicações tecnológicas, neste sentido diversos materiais cerâmicos são candidatos por suas propriedades dielétricas e ópticas. Neste presente trabalho, foram investigadas as propriedades estruturais, dielétricas e ópticas da fase ortorrômbica da matriz cerâmica ferroelétrica CaBi4Ti4O15, uma pseudo-perosviskita de estrutura de camada de bismuto (BLSFs) do grupo espacial A21am da família aurivillius, preparada pelo método do estado sólido e sinterizada em baixas temperaturas. A preparação das amostras para análise estrutural e dielétrica, tiveram a adição de pentóxido de vanádio (V2O5) à fase CaBi4Ti4O15 calcinada, em proporções de 0.5, 1.0, 1.5, 2.0 e 5.0 % em massa. Para obtenção das propriedades ópticas, a matriz cerâmica pura foi dopada com os íons terras raras érbio III (Er2O3) e óxido de itérbio III (Yb2O3). O estudo da estrutura e composição das amostras foi feito através de difração de raios-X e a confirmação da fase única foi feita pelo Refinamento Rietveld. A caracterização vibracional foi obtida através da Espectroscopia Raman (SR). O estudo da morfologia, para análise de grão e contorno de grão, foi realizado através de Microscopia Eletrônica de Varredura. A caracterização dielétrica em radio freqüência foi realizada por Espectroscopia em Impedância a qual se verificou dois mecanismos de condutividade para todas as amostras analisadas, um em baixa freqüência e outro em alta freqüência. Os modelos de relaxação dielétrica se aproximam do modelo do tipo Cole-Cole. As medidas na faixa de microondas foram obtidas utilizando-se o método hakki-coleman e monopolo, chegou-se a um coeficiente de temperatura da frequência de ressonância (tAU f) próximo de zero com adição de V2O5. As medidas de permissividade dielétrica em radiofreqüência e microondas, realizadas em temperatura ambiente, tiveram um alto valor constante (εr ≈ 150) com a adição de 1% de V2O5, e um valor da tangente de perda relativamente baixa em relação à família de Aurivillus (tan[δ] ≈10-2 ) em 2 GHz.. Uma simulação numérica foi realizada com cada amostra verificando-se aproximação com os dados experimentais. Nas amostras dopadas com terras raras foi verificado o fenômeno de conversão ascendente de energia com a presença de bandas intensas amostras de emissão de luz visível na região do verde e de bandas de menor intensidade na região do vermelho. O Material investigado tem potencial para aplicação em memórias voláteis, filtros capacitivos e componentes ópticos, como sensores, células fotoelétricas e leds.