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You searched for subject:(A2M3O12). Showing records 1 – 3 of 3 total matches.

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Pontifical Catholic University of Rio de Janeiro

1. LUCIANA PRATES PRISCO. [en] SYNTHESIS OF AL2MO3O12 NANOMETRIC POWDERS FOR OPTIMIZATION OF BULK COEFFICIENT OF THERMAL EXPANSION.

Degree: 2013, Pontifical Catholic University of Rio de Janeiro

[pt] A síntese de pós nanométricos do Al2Mo3O12 para otimização de seu coeficiente de expansão térmica na forma maciça tem como objetivo principal aproximar o comportamento térmico intrínseco e extrínseco do material. A expansão térmica intrinseca de escala atomica é medida por difração de raios-X a partir do aumento dos parametros de rede, por outro lado, a tecnica de dilatometria mede ambos os efeitos tanto intrinsecos quanto extrinsecos provenientes da microestrutura. Materiais anisotropicos apresentam coeficientes de expansão termica diferentes ao longo dos eixos cristalograficos, e com isso são encontradas maiores diferenças entre as propriedades intrinseca e maciça da expansão termica. Dessa forma a aplicação desses materias anisotropicos na forma maciça é comprometida devido a formação de microtrincas. O Al2Mo3O12 foi obtido na forma nanometrica pela síntese por coprecipitação e na forma micrométrica pela síntese de sol-gel assistido com álcool polivinilico e por reação em estado solido. Dessa forma o resultado de CET maciço obtidos pelos três métodos foram comparados entre si e também comparados aos existentes na literatura para comportamento intrínseco e maciço. Os resultados mostraram que o Al2Mo3O12 na forma nanometrica possui resultado de CET maciço muito próximo ao intrínseco, diferente do obtido para o micrométrico e também do já reportado na literatura,o que confirma que a partir de um tamanho de cristal critico não seria mais possível obter um mesmo CET intrínseco e maciço para um mesmo material.

[en] Optimization of the bulk thermal expansion coefficient of the Al2Mo3O12 using nanometric powder in order to approximate the intrinc and the extrinsic thermal properties.When a solid body is exposed to temperature variation, a change of dimensions will occur due to emergence of different effects originating at atomic (intrinsic) or microstructural (extrinsic) scales. The intrinsic thermal expansion is measured by X-ray diffraction from lattice parameters increase, on the other hand, the technique of dilatometric measures both the intrinsic as both extrinsic effects may then be defined as their CTE solid (bulk). Cubic materials exhibit isotropic behavior during thermal expansion, and thus may be insignificant variations between intrinsic and CTE s massive. Anisotropic materials have different coefficients of thermal expansion along the crystallographic axes, and presents major differences between the intrinsic properties and thermal expansion of the bulk, being mostly a bulk CTE smaller than the intrinsic one. The application of these anisotropic materials is difficult because bulk CTE massive changes expected due to formation of microcracks. The Al2Mo3O12 was obtained by three routes :coprecipitation (nanometric way) , sol-gel assisted with polyvinyl alcohol (PVA) and by solid state reaction (micrometric ways). Thus the result of bulk CET obtained by the three methods were compared and also compared with those found in the literature for intrinsic behavior and bulk. The nanometric Al2Mo3O12 showed a…

Advisors/Committee Members: BOJAN MARINKOVIC, BOJAN MARINKOVIC, BOJAN MARINKOVIC.

Subjects/Keywords: [pt] EXPANSAO TERMICA NEGATIVA; [en] NEGATIVE THERMAL EXPANSION; [pt] A2M3O12; [pt] DILATOMETRIA

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

PRISCO, L. P. (2013). [en] SYNTHESIS OF AL2MO3O12 NANOMETRIC POWDERS FOR OPTIMIZATION OF BULK COEFFICIENT OF THERMAL EXPANSION. (Thesis). Pontifical Catholic University of Rio de Janeiro. Retrieved from http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=21439

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

PRISCO, LUCIANA PRATES. “[en] SYNTHESIS OF AL2MO3O12 NANOMETRIC POWDERS FOR OPTIMIZATION OF BULK COEFFICIENT OF THERMAL EXPANSION.” 2013. Thesis, Pontifical Catholic University of Rio de Janeiro. Accessed October 31, 2020. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=21439.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

PRISCO, LUCIANA PRATES. “[en] SYNTHESIS OF AL2MO3O12 NANOMETRIC POWDERS FOR OPTIMIZATION OF BULK COEFFICIENT OF THERMAL EXPANSION.” 2013. Web. 31 Oct 2020.

Vancouver:

PRISCO LP. [en] SYNTHESIS OF AL2MO3O12 NANOMETRIC POWDERS FOR OPTIMIZATION OF BULK COEFFICIENT OF THERMAL EXPANSION. [Internet] [Thesis]. Pontifical Catholic University of Rio de Janeiro; 2013. [cited 2020 Oct 31]. Available from: http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=21439.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

PRISCO LP. [en] SYNTHESIS OF AL2MO3O12 NANOMETRIC POWDERS FOR OPTIMIZATION OF BULK COEFFICIENT OF THERMAL EXPANSION. [Thesis]. Pontifical Catholic University of Rio de Janeiro; 2013. Available from: http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=21439

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


University of North Texas

2. Rose, Kyle. Synthesis, Phase Development, and the Mechanism for Negative Thermal Expansion in Aluminum Tungstate.

Degree: 2020, University of North Texas

An in-depth study of Al2W3O12 negative thermal expansion (NTE) ceramic was performed, focused on synthesis, phase mappings, and the underlying mechanisms shown to be responsible for NTE. Review of the literature has shown inconsistencies in reported values of the dilatometry measured coefficients of thermal expansion, and the temperature for the known monoclinic to orthorhombic phase transition. Two synthesis techniques are introduced: an ionic-liquid non-hydrolytic sol-gel synthesis route; and a low temperature solid state reaction synthesis for Al2W3O12. X-ray diffraction, Raman spectroscopy, and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) were used to verify the techniques. Two differential scanning calorimetry (DSC) experiments (high and low temperature) were performed on the material showing the transition between -5 and -20 °C and no other phase changes until a reported degradation above 1100 °C. Extensive dilatometry on the material led to the discovery of elastic transitions occurring in the polycrystalline sample capable of explaining the inconsistencies in reported dilatometry results. This is further developed into a proposed model defining the regions between these transitions. Each region has a different thermal expansion as well as a direct effect on the reaction of the material upon cooling. This proposed model may allow more consistent reporting of dilatometry results for NTE materials. Raman spectroscopy was performed from 25-725 °C on the material showing both a joining in the tungsten-oxygen bending modes as well as a broadening in the tungsten-oxygen stretching modes. This is consistent with Al-O-W angle changes along the same temperature range reported in literature as well as the transverse vibrational modes responsible for NTE. Advisors/Committee Members: Reidy, Rick, Scharf, Thomas, Du, Jincheng.

Subjects/Keywords: Negative Thermal Expansion; Synthesis; Dilatometry; High Temperature Raman; Al2W3O12; A2M3O12; Vibration mechanisms

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Rose, K. (2020). Synthesis, Phase Development, and the Mechanism for Negative Thermal Expansion in Aluminum Tungstate. (Thesis). University of North Texas. Retrieved from https://digital.library.unt.edu/ark:/67531/metadc1703275/

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Rose, Kyle. “Synthesis, Phase Development, and the Mechanism for Negative Thermal Expansion in Aluminum Tungstate.” 2020. Thesis, University of North Texas. Accessed October 31, 2020. https://digital.library.unt.edu/ark:/67531/metadc1703275/.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Rose, Kyle. “Synthesis, Phase Development, and the Mechanism for Negative Thermal Expansion in Aluminum Tungstate.” 2020. Web. 31 Oct 2020.

Vancouver:

Rose K. Synthesis, Phase Development, and the Mechanism for Negative Thermal Expansion in Aluminum Tungstate. [Internet] [Thesis]. University of North Texas; 2020. [cited 2020 Oct 31]. Available from: https://digital.library.unt.edu/ark:/67531/metadc1703275/.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Rose K. Synthesis, Phase Development, and the Mechanism for Negative Thermal Expansion in Aluminum Tungstate. [Thesis]. University of North Texas; 2020. Available from: https://digital.library.unt.edu/ark:/67531/metadc1703275/

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Indian Institute of Science

3. Sumithra, S. Study Of Negative Thermal Expansion In Inorganic Framework Structure Oxides.

Degree: PhD, Faculty of Science, 2011, Indian Institute of Science

Subjects/Keywords: Inorganic Oxides - Thermal Properties; Negative Thermal Expansion (NTE); Inorganic Oxides - Thermal Expansion; A2M3O12 Oxides - Thermal Expansion; Ceramics; Y2W3O12; Inorganic Chemistry

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Sumithra, S. (2011). Study Of Negative Thermal Expansion In Inorganic Framework Structure Oxides. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/1428

Chicago Manual of Style (16th Edition):

Sumithra, S. “Study Of Negative Thermal Expansion In Inorganic Framework Structure Oxides.” 2011. Doctoral Dissertation, Indian Institute of Science. Accessed October 31, 2020. http://etd.iisc.ac.in/handle/2005/1428.

MLA Handbook (7th Edition):

Sumithra, S. “Study Of Negative Thermal Expansion In Inorganic Framework Structure Oxides.” 2011. Web. 31 Oct 2020.

Vancouver:

Sumithra S. Study Of Negative Thermal Expansion In Inorganic Framework Structure Oxides. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2011. [cited 2020 Oct 31]. Available from: http://etd.iisc.ac.in/handle/2005/1428.

Council of Science Editors:

Sumithra S. Study Of Negative Thermal Expansion In Inorganic Framework Structure Oxides. [Doctoral Dissertation]. Indian Institute of Science; 2011. Available from: http://etd.iisc.ac.in/handle/2005/1428

.