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arXiv · 2211.13387

Structural Origin of Recovered Ferroelectricity in BaTiO$_3$ Nanoparticles

H. Zhang·S. Liu·S. Ghose·B. Ravel·I. U. Idehenre·Y. A. Barnakov·S. A. Basun·D. R. Evans·T. A. Tyson
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Abstract

Nanoscale BaTiO3 particles (approximately 10 nm) prepared by ball-milling a mixture of oleic acid and heptane have been reported to have an electric polarization several times larger than that for bulk BaTiO3. In this work, detailed local, intermediate, and long-range structural studies are combined with spectroscopic measurements to develop a model structure of these materials. The X-ray spectroscopic measurements reveal large Ti off-centering as the key factor producing the large spontaneous polarization in the nanoparticles. Temperature-dependent lattice parameter changes reveal the sharpening of the structural phase transitions in these BaTiO3 nanoparticles compared to the pure nanoparticle systems. Sharp crystalline-type peaks in the barium oleate Raman spectra suggest that this component in the composite core-shell matrix, a product of mechanochemical synthesis, stabilizes an enhanced polar structural phase of the BaTiO3 core nanoparticles.

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H. Zhang, S. Liu, S. Ghose, B. Ravel, I. U. Idehenre, Y. A. Barnakov, S. A. Basun, D. R. Evans, T. A. Tyson. 2022-11-24. Structural Origin of Recovered Ferroelectricity in BaTiO$_3$ Nanoparticles. https://arxiv.org/abs/2211.13387

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