Probe Mössbauer Diagnostics of Charge Ordering in Manganites CaCuxMn7–xO12 (0 ≤ x ≤ 1)

Autor:	V. S. Rusakov, A. V. Sobolev, Igor A. Presniakov, T. V. Gubaidulina, M. E. Matsnev, I. S. Glazkova, A. M. Gapochka
Rok vydání:	2019
Předmět:	Materials science Nucleation Analytical chemistry General Physics and Astronomy chemistry.chemical_element Manganese 01 natural sciences Charge ordering chemistry Phase (matter) 0103 physical sciences Mössbauer spectroscopy Content (measure theory) 010306 general physics Phase diagram Bar (unit)
Zdroj:	Journal of Experimental and Theoretical Physics. 129:1017-1028
ISSN:	1090-6509 1063-7761
DOI:	10.1134/s1063776119110104
Popis:	We present the results of our 57Fe probe Mossbauer study in manganites CaCuxMn6.96–x57Fe0.04O12 (0 ≤ x ≤ 1). We have established that for compositions 0 ≤ x ≤ 0.15 near the structural R$$\bar {3}$$ ↔ Im$$\bar {3}$$ transition (at T ≈ TCO), an increase in the temperature leads to a decrease in the content of the rhombohedral phase (R$$\bar {3}$$) against a background of the “nucleation” and gradual increase in the fraction of the cubic phase (Im$$\bar {3}$$), in which all octahedral positions of manganese are equivalent due to the electron exchange Mn3+ ↔ Mn4+. The increase in the electron exchange frequency is assumed to be related to a weakening of the electron–lattice interaction of Jahn–Teller Mn3+ cations as x → 0.4. An increase in the copper content leads to a sharp decrease in the phase transition temperature TCO. A single component corresponding to the cubic phase (Im$$\bar {3}$$) is present in the spectrum starting from x ≥ 0.4. Based on our Mossbauer data, we have constructed a T–x phase diagram.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::322413e33d6a95a9f8c497dc853858f5 https://doi.org/10.1134/s1063776119110104 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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