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An X-ray powder and...
An X-ray powder and electron diffraction study of reduced tantalates with the perovskite structure, Na1-xSrxTaO3, 0 < x <= 0.4
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- Istomin, S. Ya. (författare)
- Moscow State University, Department of Chemistry
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- Svensson, Gunnar, 1960- (författare)
- Stockholms universitet,Institutionen för material- och miljökemi (MMK)
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- Hannerz, H (författare)
- Stockholms universitet,Institutionen för material- och miljökemi (MMK)
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- Kohler, J (författare)
- Max Planck Institute - Solid State Chemistr, Stuttgart, Germany
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(creator_code:org_t)
- Elsevier BV, 2000
- 2000
- Engelska.
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Ingår i: Journal of Solid State Chemistry. - : Elsevier BV. - 0022-4596 .- 1095-726X. ; 154, s. 427-434
- Relaterad länk:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- Single-phase perovskite-type reduced tantalates, Na1-x SrxTaO3 with 0 < x 0.4, have been synthesized by heating mixtures of NaTaO3, Sr5Ta4O15 and Ta in sealed tantalum ampules at 1400 degreesC for 20-24 h. At Sr contents of 0.5 less than or equal to x less than or equal to 0.8 and above 1400 degreesC, polyphasic samples were obtained. X-ray powder diffraction (XRD) and transmission electron microscopy studies (selected area (SAED) and convergent beam electron diffraction (CBED)) showed an orthorhombic distortion of the x = 0.1 sample (GdFeO3 type, space group Pnma). The interpretation of the XRD, SAED, and CBED studies indicates the crystallites found in the x = 0.2 and 0.3 samples to consist of domains with tetragonal and orthorhombic symmetry having the unit Cell parameters of a = b approximate to root (2a(per)) and c approximate to 2a(per) and a approximate to b approximate to root (2a(per)) and c approximate to a(per) (a(per) cell axis in the ideal perovskite structure), respectively. The x 0.4 sample was cubic (space group Pm3m) with a = a(per). Resistivity measurements showed that all samples are semiconducting and that the conductivity increases with Sr content. Magnetic measurements of Na0.6Sr0.4TaO3 revealed a diamagnetic behavior down to 20 K. Below this temperature a slight paramagnetism arises. (C) 2000 Academic Press.
Ämnesord
- NATURVETENSKAP -- Kemi -- Oorganisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)
Nyckelord
- reduced oxotantalate
- perovskite
- electron diffraction
- crystal structure
- X-ray powder diffraction
- Solid state chemistry
- Fasta tillståndets kemi
- Inorganic Chemistry
- oorganisk kemi
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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