Photo-enhanced ionic conductivity across grain boundaries in polycrystalline ceramics

2022 ◽  
Author(s):  
Thomas Defferriere ◽  
Dino Klotz ◽  
Juan Carlos Gonzalez-Rosillo ◽  
Jennifer L. M. Rupp ◽  
Harry L. Tuller
Keyword(s):  
Ionic Conductivity ◽  
Grain Boundaries ◽  
Polycrystalline Ceramics

scholarly journals Chemical and structural effects on ionic conductivity at columnar grain boundaries in yttria-stabilized zirconia thin films

2014 ◽  
Vol 122 (1426) ◽  
pp. 430-435 ◽  
Author(s):  
Takanori KIGUCHI ◽  
Yumiko KODAMA ◽  
Toyohiko J. KONNO ◽  
Hiroshi FUNAKUBO ◽  
Osamu SAKURAI ◽  
...  
Keyword(s):  
Thin Films ◽  
Ionic Conductivity ◽  
Grain Boundaries ◽  
Yttria Stabilized Zirconia ◽  
Structural Effects ◽  
Stabilized Zirconia ◽  
Columnar Grain

scholarly journals Properties of Na 0.5Bi0.5TiO3 and Na0.5Bi0.5 TiO3-based single crystals

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
J. Suchanicz ◽  
K. Kluczewska-Chmielarz ◽  
P. Czaja ◽  
M. Nowakowska-Malczyk ◽  
M. Was ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Single Crystals ◽  
Ferroelectric Materials ◽  
Processing Technology ◽  
Lead Free ◽  
Structural Defects ◽  
Polycrystalline Ceramics ◽  
Compositional Homogeneity ◽  
Piezoelectric Behavior

Most studies of ferroelectric materials were focused on polycrystalline ceramics. However, it is difficult to improve their properties significantly (particularly piezoelectric one) due to grain/grain boundaries, compositional homogeneity, isotropic characteristics, and structural defects. It is commonly accepted that single crystals often have better piezoelectric behavior and less structural defects than ceramics. In this paper, we provide the processing technology and properties of lead-free Na0.5Bi0.5TiO3 and Na0.5Bi0.5TiO 3-based single crystals. #FERROELECTRICS #NBT_SINGLE_CRYSTALS #FLUX_METHOD #CZOCHRALSKI_METHOD #DIELECTRIC_PROPERTIES

Migration of Silicate Liquid Out of Grain Boundaries in Ceramics

1999 ◽  
Vol 5 (S2) ◽  
pp. 800-801
Author(s):  
N. Ravishankar ◽  
C. Barry Carter
Keyword(s):  
Grain Boundaries ◽  
Strong Dependence ◽  
Liquid Phase Sintering ◽  
Laser Deposition ◽  
Intergranular Phase ◽  
Commercial Alumina ◽  
Special Boundaries ◽  
Polycrystalline Ceramics ◽  
Film Assembly ◽  
Twist Boundaries

Liquid-Phase Sintering (LPS) is a conventional fabrication route for the densification of alumina and other ceramics. The polycrystalline ceramics processed by LPS contain siliceous phases along the grain boundaries. This wetting of the grain boundaries has a strong dependence on the crystallography of the boundary. The liquid preferentially wets certain orientations while some special boundaries are ‘dry’. The mechanism of dewetting of these boundaries is not well understood. Several approaches have been adopted to study the nature of the liquid-solid interaction at the grain boundaries. In commercial alumina, anorthite is the most commonly found intergranular phase.Basal twist boundaries in alumina which contain a thin layer of anorthite glass have been investigated in the present study. Pulsed laser deposition has been used to deposit thin films of anorthite glass on optically flat basal sapphire. The substrate-film assembly is then bonded to an optically polished basal sapphire by sintering the assembly at 1650°C for 2h.

The interaction between basal-twin boundaries and a glassy phase in α-Alumina compacts

1988 ◽  
Vol 46 ◽  
pp. 570-571
Author(s):  
Yonn Kouh Simpson ◽  
C. Barry Carter
Keyword(s):  
Liquid Phase ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Glassy Phase ◽  
Liquid Phase Sintering ◽  
Boundary Mobility ◽  
Scientific Interest ◽  
Strong Anisotropy ◽  
Grain Boundary Mobility ◽  
Polycrystalline Ceramics

Understanding the nature of glass/crystalline interfaces is not only of fundamental scientific interest but is directly relevant to the liquid-phase sintering of polycrystalline ceramics such as α-alumina. Faceting behavior of alumina in the presence of SiO2 glass has been of much interest in the field of sintering with respect to the grain growth and the grain boundary mobility during sintering. The study of grain boundaries containing a glassy phase in alumina compacts is difficult however, since many of the TEM techniques presently available for the identification of a glassy phase at grain boundaries can give ambiguous results due to grain boundary grooving. A method for systematically studying glassy / crystalline interfaces without such ambiguity is therefore needed. Part of this study of the interaction of grain boundaries in alumina with an anorthite-based glassy phase is presented here.Previous systematic studies4 of different low-index surfaces of single crystal alumina showed that there is strong anisotropy in the faceting behavior of alumina and in the mobility of these facets in the presence of an anorthite-based glassy phase.

Grain boundaries in ceramics for solid oxide fuel cells

1993 ◽  
Vol 51 ◽  
pp. 960-961
Author(s):  
F. Tsai ◽  
J. M. Cowley ◽  
S. S. Jiang ◽  
J. B. Wagner
Keyword(s):  
Fuel Cells ◽  
Ionic Conductivity ◽  
Solid Oxide Fuel Cells ◽  
Grain Boundaries ◽  
Elevated Temperatures ◽  
Transport Number ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Secondary Phases ◽  
Ionic Conductors

Calcia stabilized zirconia(CSZ) and ceria(CeO2) doped with rare-earth oxides have been used as electrolytes in solid oxide fuel cells(SOFC). Such ceramics are usually good ionic conductors for oxygen ions at elevated temperatures. A few studies have attempted to correlate the microstructures with ionic conductivity. It was suggested that the grain boundaries play a role in depressing the ionic conductivity. In their study, it was found that continuous “thick” boundary layers of secondary phases existed on the grain boundaries and blocked ion transport.In the present studies, high resolution transmission electron microscopy has been used to investigate the microstructures of grain boundaries in zirconia doped with calcia (ZrO2 + 13%CaO) and ceria ceramics doped with calcia (CeO2 + 10% CaO). The ceramics was made in our Solid State Ionics Laboratory. Transport number measurements on zirconia samples showed that the transport number tO2- =1 from PO2 = 10-17 atm to PO2 =1 atm.

Across plane ionic conductivity of highly oriented neodymium doped ceria thin films

2015 ◽  
Vol 17 (18) ◽  
pp. 12259-12264 ◽  
Author(s):  
G. Baure ◽  
R. M. Kasse ◽  
N. G. Rudawski ◽  
J. C. Nino
Keyword(s):  
Thin Films ◽  
Ionic Conductivity ◽  
Grain Boundaries ◽  
Doped Ceria ◽  
Conductivity Measurements

Across-plane ionic conductivity measurements of PLD-grown, highly-oriented, columnar-grained Nd0.1Ce0.9O2−δ films reveal the insulating characteristics of grain boundaries in ceria electrolytes.

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