Structural, thermal and electrical properties of Pr0.5Sr0.5Co1-yNiyO3-delta perovskite-type oxides

Kostogloudis, GC; Ftikos, C

dc.contributor.author	Kostogloudis, GC	en
dc.contributor.author	Ftikos, C	en
dc.date.accessioned	2014-03-01T01:47:44Z
dc.date.available	2014-03-01T01:47:44Z
dc.date.issued	1998	en
dc.identifier.issn	0167-2738	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/25297
dc.subject	Ni-substituted praseodymium strontium cobaltite	en
dc.subject	perovskite	en
dc.subject	crystal structure	en
dc.subject	thermal expansion	en
dc.subject	electrical conductivity	en
dc.subject.classification	Chemistry, Physical	en
dc.subject.classification	Physics, Condensed Matter	en
dc.subject.other	TRANSITION-METAL COMPOUNDS	en
dc.subject.other	MAGNETIC-PROPERTIES	en
dc.subject.other	CRYSTAL-STRUCTURE	en
dc.subject.other	BAND-GAPS	en
dc.subject.other	SYSTEM	en
dc.subject.other	CONDUCTIVITY	en
dc.subject.other	NONSTOICHIOMETRY	en
dc.subject.other	ELECTRODES	en
dc.subject.other	TRANSPORT	en
dc.subject.other	LACOO3	en
dc.title	Structural, thermal and electrical properties of Pr0.5Sr0.5Co1-yNiyO3-delta perovskite-type oxides	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	1998	en
heal.abstract	Perovskite oxides in the system Pr0.5Sr0.5Co1-yNiyO3-delta (0<y<1) were prepared and characterized by X-ray powder diffraction, dilatometry and electrical conductivity measurements. The Pr0.5S0.5CoO3-delta end member has an orthorhombic GdFeO3 structure, while when Ni is substituted for Co. a tetragonal phase is formed, the concentration of which increases linearly in the range 0<y<0.6. Above y = 0.6 the tetragonal is the only phase present. The lattice parameters of all compositions were determined at room temperature. Ni is introduced in the bivalent state in the range 0<y<0.4, while Ni3+ is introduced in the range 0.4<y<1. An orthorhombic-to-tetragonal phase transition was detected by dilatometer measurements for compositions with y = 0.2, 0.4 and 0.6. The phase transition temperature decreases with increasing Ni content. The linear thermal expansion coefficient (TEC) is always higher for the high temperature modification. The formation of oxygen vacancies V-O(..)) and the concurrent thermal reduction of Co4+, Co3+ and Ni3+ cations to the lower valence states, were considered responsible for the steeper thermal expansion curves at high temperatures. The TEC generally decreases with increasing Ni content, due to the increase of the size of the unit cell. Pr0.5Sr0.5CoO3-delta and Pr0.5Sr0.5NiO3-delta end members show semi-metallic behavior, while the substitutionally-mixed compositions are semi conductors and exhibit a metal-insulator (M-I) transition when the temperature is raised. The conductivity in the semiconducting region can be described by the small polaron hopping conductivity model. The introduction of Ni2+ cations in the Co-rich compositions is preferably electronically compensated by the formation of V-O(..). (C) 1998 Elsevier Science B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	SOLID STATE IONICS	en
dc.identifier.isi	ISI:000073920800005	en
dc.identifier.volume	109	en
dc.identifier.issue	1-2	en
dc.identifier.spage	43	en
dc.identifier.epage	53	en