Perovskite-Type Ca1-xSrxNbO3(0≤x≤1) Phases: A Synthesis, Structure, and Electron Microscopy Study

S. Ya Istomin, G. Svensson, O. G. D'Yachenko, W. Holm, E. V. Antipov

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)

Abstract

Reduced niobates Ca1-xSrxNbO3(0≤x≤1) with perovskite-type structures have been synthesized at 1500°C in niobium ampoules sealed under argon gas. The prepared compounds were characterized by X-ray powder diffraction, electron diffraction, high-resolution electron microscopy, and energy-dispersive X-ray analysis. The structure of CaNbO3(GdFeO3type) was refined using X-ray powder diffraction data. Electron diffraction studies showed that complex superstructures of the perovskite-type structure occur forx>0 in Ca1-xSrxNbO3: (i) forx=0.2 and 0.3 reflections corresponding to a supercell witha≈2×√2×aper,b≈4×aper, andc≈2×√2×aper(per=ideal perovskite) were observed, (ii) forx=0.5, 0.6, and 0.7 a cubic supercell was found witha=4×aper, whereas (iii) forx=0.8 and 0.9 the supercell is probably orthorhombic witha≈c≈√2×aperandb≈2×aper. Forx=1.0 a new orthorhombic modification of SrNbO3witha≈c≈√2×a perandb≈2×aperwas found. Resistivity measurements showed CaNbO3to have a nonmetallic type of conductivity, whereas the Sr-containing samples were metallic.

Original languageEnglish
Pages (from-to)514-521
Number of pages8
JournalJournal of Solid State Chemistry
Volume141
Issue number2
DOIs
Publication statusPublished - Dec 1998
Externally publishedYes

Fingerprint

Dive into the research topics of 'Perovskite-Type Ca1-xSrxNbO3(0≤x≤1) Phases: A Synthesis, Structure, and Electron Microscopy Study'. Together they form a unique fingerprint.

Cite this