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Fritz Aldinger - One of the best experts on this subject based on the ideXlab platform.

  • electrical conduction behavior of la1 xsr1 xga3o7 δ melilite type Ceramics
    Journal of the American Ceramic Society, 2004
    Co-Authors: Michael Rozumek, Peter Majewski, Heike Schluckwerder, Fritz Aldinger, Klaus Kunstler, G Tomandl
    Abstract:

    Ceramics of the melilite-type compound La1+xSr1−xGa3O7−δ were prepared by conventional Ceramic Processing. Samples prepared represented the entire homogeneity region of the phase (i.e., x=−0.15 to 0.60). Electrochemical characterization under variable temperature and atmospheric conditions in the vicinity of air entailed four-point direct-current conductivity measurements and electromotive force measurements. La1+xSr1−xGa3O7−δ samples exhibited a p-type behavior with generally increased conductivity with increased substitution of lanthanum for strontium, which reached a saturation value of ∼10−1 S·cm−1 at 950°C.

  • la1 xsr1 xga3o7 δ melilite type Ceramics preparation composition and structure
    Journal of the American Ceramic Society, 2004
    Co-Authors: Michael Rozumek, Peter Majewski, Fritz Aldinger, Linda Sauter
    Abstract:

    Ceramic samples of the melilite-type La 1+x Sr 1-x Ga 3 O 7-δ (x = -0.15 to 0.60) compound were prepared by conventional Ceramic Processing. Sintering characteristics and microstructural evolution were studied. A phase diagram study was performed to establish the solid solubility limits as a function of the La:Sr ratio. Structural investigations of the Dalton composition as well as strontium- and lanthanum-rich samples entailed X-ray, neutron, and electron diffraction techniques at ambient and elevated temperatures. The homogeneity region was remarkably broad (x = -0.15 to 0.60) with no changes in space group observed. A small shrinkage of the unit cell was found with increased lanthanum content. Phase transitions at ambient and intermediate temperatures did not occur.

Michael Rozumek - One of the best experts on this subject based on the ideXlab platform.

  • electrical conduction behavior of la1 xsr1 xga3o7 δ melilite type Ceramics
    Journal of the American Ceramic Society, 2004
    Co-Authors: Michael Rozumek, Peter Majewski, Heike Schluckwerder, Fritz Aldinger, Klaus Kunstler, G Tomandl
    Abstract:

    Ceramics of the melilite-type compound La1+xSr1−xGa3O7−δ were prepared by conventional Ceramic Processing. Samples prepared represented the entire homogeneity region of the phase (i.e., x=−0.15 to 0.60). Electrochemical characterization under variable temperature and atmospheric conditions in the vicinity of air entailed four-point direct-current conductivity measurements and electromotive force measurements. La1+xSr1−xGa3O7−δ samples exhibited a p-type behavior with generally increased conductivity with increased substitution of lanthanum for strontium, which reached a saturation value of ∼10−1 S·cm−1 at 950°C.

  • la1 xsr1 xga3o7 δ melilite type Ceramics preparation composition and structure
    Journal of the American Ceramic Society, 2004
    Co-Authors: Michael Rozumek, Peter Majewski, Fritz Aldinger, Linda Sauter
    Abstract:

    Ceramic samples of the melilite-type La 1+x Sr 1-x Ga 3 O 7-δ (x = -0.15 to 0.60) compound were prepared by conventional Ceramic Processing. Sintering characteristics and microstructural evolution were studied. A phase diagram study was performed to establish the solid solubility limits as a function of the La:Sr ratio. Structural investigations of the Dalton composition as well as strontium- and lanthanum-rich samples entailed X-ray, neutron, and electron diffraction techniques at ambient and elevated temperatures. The homogeneity region was remarkably broad (x = -0.15 to 0.60) with no changes in space group observed. A small shrinkage of the unit cell was found with increased lanthanum content. Phase transitions at ambient and intermediate temperatures did not occur.

Derek C Sinclair - One of the best experts on this subject based on the ideXlab platform.

  • influence of nonstoichiometry on extrinsic electrical conduction and microwave dielectric loss of baco1 3nb2 3o3 Ceramics
    Journal of the American Ceramic Society, 2010
    Co-Authors: Antonio Feteira, Clive A Randall, Mehdi Mirsaneh, Soonil Lee, Michael T Lanagan, Derek C Sinclair
    Abstract:

    The microwave (MW) dielectric loss (or quality factor, Q) of BaCo1/3Nb2/3O3 (BCN) Ceramics exhibits a strong dependence on sample-Processing conditions and is not always consistent with the degree of 1:2 B-site cation ordering. Impedance spectroscopy results reveal that these BCN Ceramics exhibit remarkably different electrical properties due to low levels of nonstoichiometry induced during Ceramic Processing. These compositional changes are difficult to detect by common chemical techniques but can have a significant influence on the electrical properties, and in particular on the extrinsic electrical conduction and Q. The influence of extrinsic conduction induced by Ceramic Processing should therefore be considered when optimizing Q in MW dielectric Ceramics.

  • a link between p type electrical conduction and microwave dielectric loss in highly ordered ba co1 3nb2 3 o3 Ceramics
    Journal of Materials Research, 2010
    Co-Authors: Antonio Feteira, Mehdi Mirsaneh, Michael T Lanagan, Derek C Sinclair
    Abstract:

    BaCo1/3Nb2/3O3 Ceramics, with a high density and a similar, high degree of 1:2 B-site cation ordering, exhibit very different quality factors, Q. The Ceramics exhibit p-type behavior with higher conductivity and lower Q for samples processed in O2 as compared with those processed in air. It is proposed that unavoidable Co loss during high-temperature Ceramic Processing leads to p-type doping that must be compensated by oxygen vacancies to impede hole formation. The composition exhibiting only intrinsic conduction and optimized Q is not achieved with Processing in atmospheric oxygen due to filling of oxygen vacancies and hole formation during cooling.

G Tomandl - One of the best experts on this subject based on the ideXlab platform.

  • electrical conduction behavior of la1 xsr1 xga3o7 δ melilite type Ceramics
    Journal of the American Ceramic Society, 2004
    Co-Authors: Michael Rozumek, Peter Majewski, Heike Schluckwerder, Fritz Aldinger, Klaus Kunstler, G Tomandl
    Abstract:

    Ceramics of the melilite-type compound La1+xSr1−xGa3O7−δ were prepared by conventional Ceramic Processing. Samples prepared represented the entire homogeneity region of the phase (i.e., x=−0.15 to 0.60). Electrochemical characterization under variable temperature and atmospheric conditions in the vicinity of air entailed four-point direct-current conductivity measurements and electromotive force measurements. La1+xSr1−xGa3O7−δ samples exhibited a p-type behavior with generally increased conductivity with increased substitution of lanthanum for strontium, which reached a saturation value of ∼10−1 S·cm−1 at 950°C.

Peter Majewski - One of the best experts on this subject based on the ideXlab platform.

  • electrical conduction behavior of la1 xsr1 xga3o7 δ melilite type Ceramics
    Journal of the American Ceramic Society, 2004
    Co-Authors: Michael Rozumek, Peter Majewski, Heike Schluckwerder, Fritz Aldinger, Klaus Kunstler, G Tomandl
    Abstract:

    Ceramics of the melilite-type compound La1+xSr1−xGa3O7−δ were prepared by conventional Ceramic Processing. Samples prepared represented the entire homogeneity region of the phase (i.e., x=−0.15 to 0.60). Electrochemical characterization under variable temperature and atmospheric conditions in the vicinity of air entailed four-point direct-current conductivity measurements and electromotive force measurements. La1+xSr1−xGa3O7−δ samples exhibited a p-type behavior with generally increased conductivity with increased substitution of lanthanum for strontium, which reached a saturation value of ∼10−1 S·cm−1 at 950°C.

  • la1 xsr1 xga3o7 δ melilite type Ceramics preparation composition and structure
    Journal of the American Ceramic Society, 2004
    Co-Authors: Michael Rozumek, Peter Majewski, Fritz Aldinger, Linda Sauter
    Abstract:

    Ceramic samples of the melilite-type La 1+x Sr 1-x Ga 3 O 7-δ (x = -0.15 to 0.60) compound were prepared by conventional Ceramic Processing. Sintering characteristics and microstructural evolution were studied. A phase diagram study was performed to establish the solid solubility limits as a function of the La:Sr ratio. Structural investigations of the Dalton composition as well as strontium- and lanthanum-rich samples entailed X-ray, neutron, and electron diffraction techniques at ambient and elevated temperatures. The homogeneity region was remarkably broad (x = -0.15 to 0.60) with no changes in space group observed. A small shrinkage of the unit cell was found with increased lanthanum content. Phase transitions at ambient and intermediate temperatures did not occur.