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Updated: May 15, 2025
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Structural and Magnetic Characterization of Mechanically Alloyed (Fe2O3)1-x(Al2O3)x Solid Solutions via Pulsed
Dong Luo1, Hayato Nakaishi1, Takeshi Yabutsuka1
1Graduate School of Energy Science, Kyoto University, Kyoto 606-8501, Japan.
Abstract:
Neutron powder diffraction experiments were carried out to characterize mechanochemically synthesized (Fe2O3)1-x(Al2O3)x solid solutions with corundum-type structure, focusing on their lattice and magnetic structures with varying temperature and composition. The neutron diffraction experiments for (Fe2O3)0.5(Al2O3)0.5 in the temperature range between 4 K and 300 K reveal that no significant structural phase transition occurred. The behavior of temperature variation of lattice parameters is different from α-Fe2O3 and α-Al2O3 and reveals the thermal expansion coefficients of α = 5.76(2) × 10-6 K-1 and α = 6.19(5) × 10-6 K-1 between 200 K and 300 K. The room temperature neutron diffraction of (Fe2O3)1-x(Al2O3)x shows a linear decrease in lattice parameters with the aluminum substitution, following Vegard's law, along with a decrease in the magnetic moment, indicating the dilution effect on spin interactions. With the increase in the aluminum substitution from x = 0 to 0.5, the deduced magnetic moment decreases from 2.224 μB to 0.862 μB.
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