Defects and electrical conduction in mixed lanthanum transition metal oxides

Gaur, Kanchan; Verma, Smriti; Lal, H. B.

doi:10.1007/bf01115712

Cited by 58 publications

(11 citation statements)

References 11 publications

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“…Orthoferrites can be either p- or n-type semiconductors, as indicated by Seebeck coefficient measurements. , The n-type LnFeO 3 compounds exhibit a remarkable activity for methanol-sensing above the Néel temperature ( T N ) of these oxides . The sensing activity appeared in the temperature ranges in which these oxides show paramagnetic behaviors.…”

Section: E Chemical Sensorsmentioning

confidence: 99%

Chemical Structures and Performance of Perovskite Oxides

2001

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He obtained his Ph.D. in chemistry in 1990 at the same university, working under the supervision of Dr. L. Gonza ´lez Tejuca and Prof. J. L. G. Fierro at the Institute of Catalysis and Petrochemistry (CSIC). From 1990 to 1993, he was working under contract in a project of oxidative coupling of methane funded by REPSOL (the largest Spanish oil and petrochemisty company). At the end of this period, he got a staff position of researcher in the Institute of Catalysis and Petrochemisty, that is his current status. In 1996−1997, he was a Visiting Scholar in the group of Prof. A. Varma, at the University of Notre Dame (USA). He has been the Head of the Department of Sturcture and Reactivity of the Institute of Catalysis and Petrochemistry since 1998. His research interests are focused mainly in catalytic processes for clean energy production, specifically in catalytic applications of perovskite oxides (Ph.D. dissertation), natural gas conversion, catalytic combustion, C 1 chemistry, catalyic membrane reactors, hydrogen production, and fuel cell catalysts. He has published 30 papers and 3 patents and made 22 presentations at symposia and conferences.

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Section: E Chemical Sensorsmentioning

confidence: 99%

Chemical Structures and Performance of Perovskite Oxides

2001

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“…A linear dependence of log( σT ) against 1/ T was reported in LaCrO 3 ‐based ceramics, and such a character was believed to be an indicator of the thermally activated hopping of small polarons as the conduction mechanism 48,49 . In this study, the linear relationship is not strictly satisfied in the temperature range between room temperature and 1923 K, as shown in the insets of Figure 5, indicating a more complex conduction mechanism.…”

Section: Resultsmentioning

confidence: 57%

Sintering temperature–induced structural transition in LaCrO₃‐based conducting oxides synthesized from nano‐powders

Liu

Zhai

et al. 2023

J Am Ceram Soc.

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Preparation condition plays a critical role in the structure and properties of ceramics. However, exactly how it affects lanthanum chromate (LaCrO3)‐based conducting oxides remains poorly understood. In this work, the effects of sintering temperature on the crystal structure, microstructure, and electrical conductivity of pure and Sr2+‐/Ca2+‐substituted LaCrO3 ceramics have been investigated. It is found that the calcining temperature can be reduced by 200–300 K to obtain a single‐perovskite structure by using nano‐powders as raw materials. A sintering temperature–induced structural transition from orthorhombic Pbnm phase to rhombohedral Rtrue3¯c$R\bar 3c$ phase is found in La0.8Sr0.2CrO3, and the possible mechanism is attributed to a thermally induced transformation of the thermodynamic metastable orthorhombic to stable rhombohedral phase after thermal treatment at higher temperatures. The electrical conductivity in a broad temperature range (from room temperature up to 1923 K) is measured. The conductivity increases with the elevated sintering temperature and soaking time, and it shows a remarkable enhancement by introducing the Sr and Ca ions. These results suggest that the sintering temperature should be well controlled and optimized to obtain desired crystal structure and electrical conductivity in LaCrO3‐based materials for various applications.

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“…Fe ions have such a lower mobility than Co ions that the reported mobility of electrical holes of LaFeO 3 is lower than that of LaCoO 3 by approximately three orders of magnitude. 211 Choi et al 168 investigated the synergetic effect of co-doping both A- and B-sites on the electrochemical properties of PrBaCo 2 O 5+ δ . Partially substituting Ba with Sr and Co with Fe in PrBaCo 2 O 5+ δ created oxygen vacancy (pore) channels in the [PrO] and [CoO] planes that significantly enhanced the oxygen ion diffusion and surface oxygen exchange resulting in a peak power density of ∼2.9 W cm −2 at 650 °C.…”

Section: Double Perovskite-type Structure Sofc Cathodesmentioning

confidence: 99%