High-temperature heat capacity of Co3O4 spinel: thermally induced spin unpairing transition

K. Mocala; A. Navrotsky; D. M. Sherman

doi:10.1007/BF00198606

High-temperature heat capacity of Co₃O₄ spinel: thermally induced spin unpairing transition

K. Mocala, A. Navrotsky, D. M. Sherman

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Abstract

A strong anomaly was found in the heat capacity of Co₃O₄ between 1000 K and the decomposition temperature. This anomaly is not related to the decomposition of Co₃O₄ to CoO. The measured entropy of transition, ΔS=46±4 J mol^-1 K^-1 of Co₃O₄, supports the interpretation that this anomaly reflects a spin unpairing transition in octahedrally coordinated Co³⁺ cations. Experimental values of heat capacity, heat content and entropy of Co₃O₄ in the high temperature region are provided. The enthalpy of the spin unpairing transition is 53±4 kJ mol^-1 of Co₃O₄.

Original language	English (US)
Pages (from-to)	88-95
Number of pages	8
Journal	Physics and Chemistry of Minerals
Volume	19
Issue number	2
DOIs	https://doi.org/10.1007/BF00198606
State	Published - Aug 1992
Externally published	Yes

ASJC Scopus subject areas

Materials Science(all)
Geochemistry and Petrology

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title = "High-temperature heat capacity of Co3O4 spinel: thermally induced spin unpairing transition",

abstract = "A strong anomaly was found in the heat capacity of Co3O4 between 1000 K and the decomposition temperature. This anomaly is not related to the decomposition of Co3O4 to CoO. The measured entropy of transition, ΔS=46±4 J mol-1 K-1 of Co3O4, supports the interpretation that this anomaly reflects a spin unpairing transition in octahedrally coordinated Co3+ cations. Experimental values of heat capacity, heat content and entropy of Co3O4 in the high temperature region are provided. The enthalpy of the spin unpairing transition is 53±4 kJ mol-1 of Co3O4.",

author = "K. Mocala and A. Navrotsky and Sherman, {D. M.}",

year = "1992",

month = aug,

doi = "10.1007/BF00198606",

language = "English (US)",

volume = "19",

pages = "88--95",

journal = "Physics and Chemistry of Minerals",

issn = "0342-1791",

publisher = "Springer Verlag",

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TY - JOUR

T1 - High-temperature heat capacity of Co3O4 spinel

T2 - thermally induced spin unpairing transition

AU - Mocala, K.

AU - Navrotsky, A.

AU - Sherman, D. M.

PY - 1992/8

Y1 - 1992/8

N2 - A strong anomaly was found in the heat capacity of Co3O4 between 1000 K and the decomposition temperature. This anomaly is not related to the decomposition of Co3O4 to CoO. The measured entropy of transition, ΔS=46±4 J mol-1 K-1 of Co3O4, supports the interpretation that this anomaly reflects a spin unpairing transition in octahedrally coordinated Co3+ cations. Experimental values of heat capacity, heat content and entropy of Co3O4 in the high temperature region are provided. The enthalpy of the spin unpairing transition is 53±4 kJ mol-1 of Co3O4.

AB - A strong anomaly was found in the heat capacity of Co3O4 between 1000 K and the decomposition temperature. This anomaly is not related to the decomposition of Co3O4 to CoO. The measured entropy of transition, ΔS=46±4 J mol-1 K-1 of Co3O4, supports the interpretation that this anomaly reflects a spin unpairing transition in octahedrally coordinated Co3+ cations. Experimental values of heat capacity, heat content and entropy of Co3O4 in the high temperature region are provided. The enthalpy of the spin unpairing transition is 53±4 kJ mol-1 of Co3O4.

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DO - 10.1007/BF00198606

M3 - Article

AN - SCOPUS:0037575022

SN - 0342-1791

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SP - 88

EP - 95

JO - Physics and Chemistry of Minerals

JF - Physics and Chemistry of Minerals

IS - 2

ER -

High-temperature heat capacity of Co₃O₄ spinel: thermally induced spin unpairing transition

Abstract

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