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arXiv · 1510.01572

On the influence of inversion on thermal properties of magnesium gallium spinel

Linda Schwarz·Zbigniew Galazka·Thorsten M. Gesing·Detlef Klimm
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Abstract

Measurements of thermal diffusivity \k{appa} (using laser flash analysis) for temperatures from 100 °C to 1200 °C and of the inversion parameter x (using X-ray analysis) for the single crystal spinel MgGa2O4 have been performed. X-ray analysis showed a small change in x for samples annealed at 800 °C (x = 0.838) and 1200 °C (x = 0.834). Thermal diffusivity revealed a significant rise of \k{appa} for temperatures higher than 950 °C, deviating from the typical 1/T drop of \k{appa}. An additional systematic rise of \k{appa} with time is observed for temperatures between 950 °C and 1100 °C. A connection between cation disordering processes typical for spinels at elevated temperatures and the observed deviation of \k{appa} is proposed: Data indicate that cations changing their occupancy site at equilibration processes contribute significantly to \k{appa} and therefore represent a new type of heat transport.

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Linda Schwarz, Zbigniew Galazka, Thorsten M. Gesing, Detlef Klimm. 2015-10-06. On the influence of inversion on thermal properties of magnesium gallium spinel. https://doi.org/10.1002/crat.201500275

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