Influence of Sintering on Electrical Properties and Phase Transition of La2Mo2O9

2006 ◽  
Vol 530-531 ◽  
pp. 520-525 ◽  
Author(s):  
R.A. Rocha ◽  
E.N.S. Muccillo
Keyword(s):  
Phase Transition ◽  
Ionic Conductivity ◽  
Solid Oxide Fuel Cells ◽  
Strong Dependence ◽  
Structural Phase ◽  
Relative Magnitude ◽  
High Ionic Conductivity ◽  
Polymeric Precursor ◽  
Lanthanum Molybdate ◽  
Sintering Conditions

High ionic conductivity ceramics have potential technological applications in chemical sensors, ceramic permeable membranes, oxygen pumps, and solid oxide fuel cells. Recently ionic conductivity values as high as those of doped zirconia solid solutions have been found in a lanthanum molybdate compound. The high ionic conductivity of this compound, La2Mo2O9, is obtained at temperatures above the structural phase transition temperature (~580 °C). In this work the La2Mo2O9 ceramic material was prepared by the polymeric precursor technique and sintered at several dwell temperatures and soaking times to study the effect of sintering conditions on phase transition. It was found that there is a strong dependence of phase transition on the sintering profile. At 950 °C the phase transition is suppressed for short soaking times, whereas it is observed to occur for longer times. Moreover, the relative magnitude of conductivity is also dependent on the sintering conditions. The main conclusion is that the phase transition in La2Mo2O9 is particle sizedependent.

scholarly journals Structural phase transitions and conducting properties in Bimetallic sulfates

2014 ◽  
Vol 70 (a1) ◽  
pp. C74-C74
Author(s):  
Vaishali Sharma ◽  
Diptikanta Swain ◽  
Chandrabhas Narayana ◽  
Tayur Guru Row
Keyword(s):  
Phase Transitions ◽  
Ionic Conductivity ◽  
Structural Phase ◽  
Functional Materials ◽  
High Ionic Conductivity ◽  
Monoclinic Space Group ◽  
Structural Phase Transitions ◽  
Space Group ◽  
Ion Conducting ◽  
Fast Ion

Bimetallic sulfate minerals, hydrated as well as anhydrous are important multifunctional materials which exhibit interesting properties like fast-ion conduction, ferroelectricity and magnetism with variation in temperature [1,2,3]. These properties are generally entwined with structural phase transitions and show structural frameworks made of interconnection of octahedra and tetrahedra [1]. Bimetallic sulfates, indeed are intercalation compounds of alkali ions generated by these frameworks and they possess high ionic conductivity [1]. In the present study, anhydrous and hydrous compounds of Na6M(SO4)4, (M=Mn, Ni, Co) were synthesized to understand the structural phase transitions and its relation to fast-ion conducting properties. Na6Mn(SO4)4, is monoclinic, space group P21/c with Z=2 and is isostructural to its Co and Ni analogues and shows high ionic conductivity and structural phase transition > 4500C. Na6Co(SO4).2H2O, Na6Ni(SO4).2H2O are isostructural with triclinic system having space group P-1 with Z =1. In addition, structural features and correlation with ionic conductivity in Na6Co(SO4).2H2O, Na6Ni(SO4).2H2O and Na6Mn(SO4) will be outlined. These studies open up the utility of hydrated bimetallic sulfates as possible precursor for the design of functional materials.

scholarly journals Ceria co-doping: synergistic or average effect?

2014 ◽  
Vol 16 (18) ◽  
pp. 8320-8331 ◽  
Author(s):  
Mario Burbano ◽  
Sian Nadin ◽  
Dario Marrocchelli ◽  
Mathieu Salanne ◽  
Graeme W. Watson
Keyword(s):  
Fuel Cells ◽  
Ionic Conductivity ◽  
Solid Oxide Fuel Cells ◽  
State Of The Art ◽  
Solid Oxide ◽  
High Ionic Conductivity ◽  
Oxide Fuel ◽  
Average Effect ◽  
Co Doping ◽  
Viable Approach

High ionic conductivity of the electrolyte is a requisite for cheap, reliable and efficient solid oxide fuel cells. In this study we show that co-doping is not a viable approach to increase the conductivity of state-of-the-art electrolyte material, ceria.

Atmospheric plasma-sprayed La0.8Sr0.2Ga0.8Mg0.2O3 electrolyte membranes for intermediate-temperature solid oxide fuel cells

2015 ◽  
Vol 3 (14) ◽  
pp. 7535-7553 ◽  
Author(s):  
Shan-Lin Zhang ◽  
Tao Liu ◽  
Chang-Jiu Li ◽  
Shu-Wei Yao ◽  
Cheng-Xin Li ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Ionic Conductivity ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Intermediate Temperature ◽  
High Ionic Conductivity ◽  
Atmospheric Plasma ◽  
Oxide Fuel ◽  
Electrolyte Membranes ◽  
Plasma Sprayed

La0.8Sr0.2Ga0.8Mg0.2O3 (LSGM) is considered a promising electrolyte material for intermediate-temperature solid oxide fuel cells (IT-SOFCs) because of its high ionic conductivity.

scholarly journals High Performance Low-Temperature Solid Oxide Fuel Cells Based on Nanostructured Ceria-Based Electrolyte

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2231
Author(s):  
Jiamei Liu ◽  
Chengjun Zhu ◽  
Decai Zhu ◽  
Xin Jia ◽  
Yingbo Zhang ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Ionic Conductivity ◽  
Low Temperature ◽  
Solid Oxide Fuel Cells ◽  
Nanocrystalline Structure ◽  
Solid Oxide ◽  
High Ionic Conductivity ◽  
Oxide Fuel ◽  
Pure Ceo2 ◽  
Co Doped

Ceria based electrolyte materials have shown potential application in low temperature solid oxide fuel cells (LT-SOFCs). In this paper, Sm3+ and Nd3+ co-doped CeO2 (SNDC) and pure CeO2 are synthesized via glycine-nitrate process (GNP) and the electro-chemical properties of the nanocrystalline structure electrolyte are investigated using complementary techniques. The result shows that Sm3+ and Nd3+ have been successfully doped into CeO2 lattice, and has the same cubic fluorite structure before, and after, doping. Sm3+ and Nd3+ co-doped causes the lattice distortion of CeO2 and generates more oxygen vacancies, which results in high ionic conductivity. The fuel cells with the nanocrystalline structure SNDC and CeO2 electrolytes have exhibited excellent electrochemical performances. At 450, 500 and 550 °C, the fuel cell for SNDC can achieve an extraordinary peak power densities of 406.25, 634.38, and 1070.31 mW·cm−2, which is, on average, about 1.26 times higher than those (309.38, 562.50 and 804.69 mW·cm−2) for pure CeO2 electrolyte. The outstanding performance of SNDC cell is closely related to the high ionic conductivity of SNDC electrolyte. Moreover, the encouraging findings suggest that the SNDC can be as potential candidate in LT-SOFCs application.

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