ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Effects of Octahedral Tilting on the Piezoelectric Properties of Strontium/Barium/Niobium-Doped Soft Lead Zirconate Titanate Ceramics (2002)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 85 (2002), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: (Pb1−x−ySrxBay)(Zr0.976−zTizNb0.024)O3 solid solutions have been investigated to understand the relationship between structural changes caused by isovalent strontium and barium substitution on the A-site and dielectric and piezoelectric properties. As strontium and barium were substituted for lead, the zirconium:titanium (Zr:Ti) ratio was modified so that all compositions had an optimized piezoelectric coefficient (d33). The value of d33 was at a maximum in the tetragonal phase near, but not at, the morphotropic-phase boundary (MPB). The real MPB was taken as the Zr:Ti ratio at which X-ray diffraction patterns appeared either pseudocubic or a mixture of rhombohedral and tetragonal. As strontium content increased, optimized d33 also increased from 410 pC/N (x= 0) to 640 pC/N (x= 0.12), commensurate with a decrease in the paraelectric-to-ferroelectric phase transition temperature (TC) from 350°C (x= 0) to 175°C (x= 0.12). However, for ceramics where x 〉 0.12, optimized d33 decreased even though the phase-transition temperature was ∼150°C. Low strontium concentration ceramics (x= 0–0.08) contained 80 nm ferrroelectric domains typical of PZT, but high strontium concentration ceramics (x= 0.12–0.16) contained fine-scale domains (20 nm) in some regions of the microstructure. In addition, [110] pseudocubic electron diffraction patterns revealed superlattice reflections at 1/2{hkl} positions associated with rotations of the octahedra in antiphase. Co-doping ceramics with strontium (x= 0.06) and barium (y= 0.06) resulted in the disappearance of the 1/2{hkl} reflections. Optimized d33 (∼520 pC/N, TC∼ 205°C) for this composition was similar to that of ceramics where x= 0.08, y= 0, which had a TC of ∼250°C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2002.tb00457.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Surface Decomposition of Strontium-Doped Soft PbZrO3–PbTiO3 (2002)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 85 (2002), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Sintering temperature has a pronounced effect on perovskite phase stability at the surface of Pb0.88Sr0.12Zr0.54Ti0.44Sb0.02O3 (PSZT) soft piezoelectric ceramics (d33≈ 600 pC/N). After sintering 4 h at 1070°C, XRD reveals only perovskite PSZT peaks in the bulk and at the surface. As sintering temperature increases, XRD from the ceramic surface reveals a second-phase peak at ∼27° (2θ), 0.316 nm (d-spacing). After 4 h at 1280°C, further second-phase peaks are observed, confirming it to be monoclinic ZrO2, accompanied by a strong increase in the degree of tetragonality of the perovskite phase. These observations are consistent with decomposition of the PSZT to ZrO2 and tetragonal PZT (PbZrO3–PbTiO3) associated with PbO loss. SEM and cross-sectional TEM indicated that surface decomposition had progressed ∼0.5 mm into the sample after 4 h at 1280°C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2002.tb00067.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Microstructural Evolution in Triaxial Porcelain (2000)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 83 (2000), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Microstructural evolution in a model triaxial porcelain was studied by X-ray diffractometry and electron microscopy of quenched samples after firing for 3 h at 600°–1500°C. The clay component dehydroxylated to metakaolin at ∼550°C. Metastable sanidine formed from decomposition of the feldspar at 〉600°C and dissolved at 〉900°C. Liquid formation at ∼1000°C was associated with melting of feldspar and silica discarded from metakaolin formation via the K2O–Al2O3–SiO2 eutectic. Liquid content increased at 1000°–1200°C with further feldspar melting and additionally at 〉1200°C because of quartz dissolution. Small (≤7 nm) mullite and γ-alumina crystals precipitated in pure clay relicts and larger (≤30 nm) mullite crystals in mixed clay-feldspar relicts at 1000°C. In the evolving microstructures, three regions were observed. These regions were derived from pure clay relicts containing primary (type-I) mullite; feldspar-penetrated clay relicts, also containing secondary (granular type-II) mullite; and the matrix of fine clay, feldspar, and quartz, containing secondary (granular type-II and elongated type-III) mullite. In addition to shape, the mullite size changed, increasing from regions containing type-I to type-III mullite, because the increasingly fluid liquid enhanced crystal growth. Below 1300°C, primary mullite was richer in Al2O3 than the secondary mullite, and the glass composition was inhomogeneous, with the K2O and Al2O3 contents varying throughout the microstructure. Above 1400°C, mullite began to dissolve.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2000.tb01692.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Glass-Ceramic Formation in the ZnO-P2O5 System and the Effect of Silica as a Nucleating Agent (1999)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 82 (1999), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Crystallization of a series of ZnO-P2O5 based glasses was investigated. ZnO-P2O5-CaO glasses could be converted most readily to glass-ceramics and crystallization of these led to formation of alpha-Zn2P2O7, alpha-CaZn2(PO4)2, and ß-CaZn2(PO4)2 phases. A further phase has been tentatively identified as monoclinic (Zn,Ca)2P2O7. The most promising glass-ceramic composition Z15 (59.4ZnO·33P2O5·6.6CaO·1SiO2) crystallized to alpha-Zn2P2O7 and ß-CaZn2(PO4)2, the latter phase being stabilized by the presence of SiO2 which also encouraged volume nucleation giving a fine-scale (submicrometer) microstructure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1999.tb02068.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Space Group Determination of Ba6-3xNd8+2xTi18O54 (1999)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 82 (1999), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The space group of the solid solution phase Ba6-3x-RE8+2xTi18O54(RE = rare-earth cation) has been variously reported as Pba2 (No. 32), Pbn21(No. 33), Pbam (No. 55), or Pbnm (No. 62). New results are presented here which indicate that its correct space group assignment may be Pb21m (No. 26).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1999.tb01918.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Fired Porcelain Microstructures Revisited (1999)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 82 (1999), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The microstructure of standard commercial porcelain consists of alpha-quartz grains held in a complex matrix. Quartz grains are surrounded by amorphous silica-rich solution rims while the matrix contains clay relicts of small (~200 nm × 40 nm × 40 nm) primary (2Al2O3:1SiO2) mullite crystals in aluminosilicate glass and feldspar relicts of acicular (〉1 µm long) secondary (3Al2O3:2SiO2) mullite in potassium aluminosilicate glass. A continuous increase in mullite crystal size from the clay-feldspar relict interface to the feldspar relict center and their compositions indicate a transformation from primary to secondary mullite. In aluminous porcelain, corundum grains are observed in addition to alpha-quartz and regions of clay and feldspar relicts. Small (~50 nm × 10 nm × 10 nm) tertiary mullite crystals (formed by precipitation from Al2O3-rich glass) were detected adjacent to these corundum grains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1999.tb02282.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Influence of Additives on Slag Resistance of Al2O3-SiO2-SiC-C Refractory Bond Phases under Reducing Atmosphere (1998)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 81 (1998), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The microstructures of Al2O3–SiO2–SiC–C refractory matrices with aluminum, silicon, Si3N4, BN, B2O3, and B4C additives are characterized before and after a crucible slag test, and the phases present are compared to those expected at thermodynamic equilibrium. The carbon content dominates the resistance to CaO–MgO–Al2O3–SiO2 slag penetration, while the viscosity of liquid phases present has a significant influence when the matrix carbon contents are similar. Silicon and Si3N4 additives reduce slag penetration resistance because of indirect oxidation of carbon to form SiC. B4C, in particular, and B2O3 also reduce slag penetration resistance because of formation of a more fluid boron-containing liquid, while aluminum and BN addition have no significant effect. Carbon and BN hardly react with the slag, while SiC partially reacts with it, leading to deposition of carbon as a dense layer. Corundum present in the refractories also readily dissolves in the slag. Microstructurally, slag penetration resistance is associated with the dense carbon layer located at the slag-refractory interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1998.tb02754.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Corrosion of MgO—MgAl2O4 Spinel Refractory Bricks by Calcium Aluminosilicate Slag (1997)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 80 (1997), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Microstructural analysis of MgO—MgAl2O4 refractory bricks corroded at 1400–1450°C by calcium aluminosilicate slag reveals secondary spinel, monticellite, merwinite, and MgO as microscopic corrosion products, generally forming in this sequence as the brick is penetrated. The secondary spinel forms an incomplete layer close to (but not at) the MgO grain. Thermodynamic calculations are used to support a detailed model of the corrosion mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1997.tb02852.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Synthesis of Magnesium Aluminate Spinel Platelets from α-Alumina Platelet and Magnesium Sulfate Precursors (2003)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 86 (2003), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Spinel platelets were formed from a powder mixture of 3–5 μm wide and 0.2–0.5 μm thick α-Al2O3 and 1–8 μm (average 3 μm) MgSO4 heated 2 h at 1200°C. The hexagonal platelet shape of the original α-Al2O3 platelet was maintained in the spinel, although their size was slightly increased and their surface roughened. When a mixture of α-Al2O3 platelets and MgO powder was heated 3 h at 1400°C, the spinel formed lost the platelet morphology of the alumina.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2003.tb03589.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Complex Phase Equilibria in Refractories Design and Use (2002)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 85 (2002), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The current applications of phase diagrams and thermodynamic calculations to studies of refractories are reviewed highlighting links to microstructural analyses. Improved understanding of microstructural evolution and chemical corrosion mechanisms has resulted from such work. The limitation of the calculations/diagrams to thermodynamic equilibria has led to imaginative attempts to incorporate some dynamic aspect in them so they are more relevant to practical conditions. These include varying temperature to model a temperature gradient, PO2 to model atmosphere permeation into a brick, slag/refractory ratio to model slag penetration and altering the slag composition after reaction with the fine matrix phases. The potential future development of such techniques is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2002.tb00555.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...