Title

AVALIAÇÃO TERMODINÂMICA DO SISTEMA Al2O3-MnO - PROPRIEDADES TERMODINÂMICAS DO ÓXIDO Al2MnO4

THERMODYNAMICA EVALUATION OF THE SYSTEM Al2O3 – MnO: THERMODYNAMIC PROPERTIES OF THE OXIDE Al2MnO4

Authorship

Siqueira, Rogério Navarro Correia de; Avillez, Roberto Ribeiro de; Gomes, Angelo Marcio de Souza

DOI

10.5151/2594-5327-14917

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Abstract

In the present work data for the heat capacity at constant pressure of the oxide Al2MnO4 were measured in the range between 2 K and 300 K. Two peaks were detected, one around 30 K, and the other around 6 K. The comparison with studies on similar materials suggested, that the observed phenomenon is magnetic in nature. By separate modeling of the vibrational and magnetic contributions it was possible to calculate the molar formation entropy at 298 K, which was equal to 117,3 ± 0,9 J/mol.K. This value is 10% higher than the accepted estimations from the literature. The authors believe that the difference must be associated with the magnetic entropy, whi

 

In the present work data for the heat capacity at constant pressure of the oxide Al2MnO4 were measured in the range between 2 K and 300 K. Two peaks were detected, one around 30 K, and the other around 6 K. The comparison with studies on similar materials suggested, that the observed phenomenon is magnetic in nature. By separate modeling of the vibrational and magnetic contributions it was possible to calculate the molar formation entropy at 298 K, which was equal to 117,3 ± 0,9 J/mol.K. This value is 10% higher than the accepted estimations from the literature. The authors believe that the difference must be associated with the magnetic entropy, which is a consequence of the observed anomalies in the heat capacity data.

Keywords

Entropia magnética; Capacidade calorífica; Al2MnO4.

Magnetic entropy; Heat capacity; Al2MnO4.