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.
@article{arxiv.2211.13387,
title = {Structural Origin of Recovered Ferroelectricity in BaTiO$_3$ Nanoparticles},
author = {H. Zhang and S. Liu and S. Ghose and B. Ravel and I. U. Idehenre and Y. A. Barnakov and S. A. Basun and D. R. Evans and T. A. Tyson},
journal= {arXiv preprint arXiv:2211.13387},
year = {2023}
}
Comments
5 figures in main text. 1 table and 4 figures in supplementary document