A high-resolution synchrotron X-ray diffraction study of a single-crystal YCrO3 compound was employed to obtain its crystallographic information, such as lattice parameters, atomic positions, bond lengths and angles, and local crystalline distortion size and mode. The measurements were taken at 120 K (below the antiferromagnetic transition temperature T N ≃ 141.5 K), 300 K (between T N and the ferroelectric transition temperature T C ≃ 473 K) and 500 K (above T C). Using the high intensity of synchrotron X-rays, it was possible to refine collected patterns with the previously proposed noncentrosymmetric monoclinic structural model (P1211, No. 4) and determine detailed structural parameters. Meanwhile, for a controlled study, the data were refined with the centrosymmetric orthorhombic space group (Pmnb, No. 62). The lattice constants a, b and c and the unit-cell volume increased nearly linearly upon heating. With the P1211 space group, the distributions of bond lengths and angles, as well as local distortion strengths, were observed to be more dispersed. This implies that (i) the local distortion mode of Cr2O6 at 120 K correlates with the formation of canted antiferromagnetic order by Cr1–Cr2 spin interactions, primarily via intermediate O3 and O4 ions; and (ii) the previously reported dielectric anomaly may have a microscopic origin in the strain-balanced Cr1—O3(O4) and Cr2—O5(O6) bonds as well as the local distortion modes of Cr1O6 and Cr2O6 octahedra at 300 K. Local crystalline distortion is shown to be an important factor in the formation of ferroelectric order. The comprehensive set of crystallographic information reported here allows for a complete understanding of the unique magnetic and ferroelectric properties of YCrO3.
The solid‐state battery (SSB) is a promising direction to address the inherent safety problems in commercial batteries and energy storage systems. However, the development of SSBs is still hider of the low ionic conductivity of solid‐state electrolytes. Based on a machine learning (ML) method, a cobalt‐doping strategy was developed for the Na3.2Zr2Si2.2P0.8O12 (NASICON) compound by training on NASICON‐type solid electrolyte data. The cobalt‐doping strategy efficiently improves the NASICONs’ ionic conductivity to ∼2.63 mS/cm with low activation energy at ∼0.245 eV. The grain‐boundary ionic conductivity reaches ∼11.00 mS/cm without extra densification of the pellet. The NASICON's structures were studied by the Rietveld and the bond‐valence methods. The calculations and observed structural transitions confirm that the cobalt‐doping strategy promotes the structural transition and adjusts the structure to a better performance state. The doping strategy predicted by the ML model is consistent with our experimental results, providing very useful guidance for improving ionic conductivity of NASICON electrolytes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.