Valence state equilibria between cobalt and manganese ions and magnetic properties of LaCo{sub 0.9}Mn{sub 0.1}O{sub 3}

Journal Article · Tue Nov 01 04:00:00 EST 1994 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1994.1362· OSTI ID:508651

Jia, Y Q ^[1]; Liu, S T ^[2]; Wu, Y ^[3]

---

1. East China Univ. of Science and Technology, Shanghai (China)
2. Dalian Inst. of Chemical Physics (China)
3. Academia Sinica, Changchun (China)

According to the thermodynamic equilibria between the low spin state Co{sup III} (t{sub 2g}{sup 6}e{sub g}{sup o}) ion and the high spin state Co{sup 3} (t{sub 2g}{sup 4}e{sub g}{sup 2}) ion and between the cobalt and manganese ions with different valence state and spin state, an approximate semiempirical formula has been proposed to calculate the magnetic susceptibilities of La Co{sub 0.9}Mn{sub 0.1}O{sub 3} in a wide temperature range (100-1200 K). The results show that the calculated susceptibilities of LaCo{sub 0.9}Mn{sub 0.1}O{sub 3} are very close to the experimental susceptibilities, and the relative errors are smaller than 5%, except in a few cases. In LaCo{sub 0.9}Mn{sub 0.1}O{sub 3} there may exist the low spin state Co{sup 111} ion, the high spin state Co{sup 3+} and CO{sup 2+} ions, and the high spin state Mn{sup 3+} and Mn{sup 4+} ions at different temperatures. The content of the low spin state Co{sup III} ion has been predominant in LaCo{sub 0.9}Mn{sub 0.1}O{sub 3} in the whole temperature range, and decreases gradually with increasing temperature. At lower temperatures, the content of the Mn{sup 4+} ion in LaCo{sub 0.9}Mn{sub 0.1}O{sub 3} is larger than that of the Mn{sup 3+} ion; however, at higher temperatures, the manganese ion is mainly trivalent. The calculated results are in good agreement with some experimental results; for example, the effective paramagnetic moment of the compound agrees with the paramagnetic Curie point of the compound. The temperature dependence of the electric resistivity of LaCo{sub 0.5}Mn{sub 0.1}O{sub 3} has also been predicted.

• OSTI ID: 508651
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 113; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COBALT OXIDES
CURIE POINT
ELECTRIC CONDUCTIVITY
EQUILIBRIUM
LANTHANUM OXIDES
MAGNETIC SUSCEPTIBILITY
MANGANESE OXIDES
MATHEMATICAL MODELS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
VALENCE