Muraoka Keita, Kanki Teruo
Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan.
Sci Rep. 2019 Dec 27;9(1):20093. doi: 10.1038/s41598-019-56685-4.
Vanadium dioxide (VO) is a strongly correlated electronic material with a metal-insulator transition (MIT) near room temperature. Ion-doping to VO dramatically alters its transport properties and the MIT temperature. Recently, insulating hydrogenated VO (HVO) accompanied by a crystal structure transformation from VO was experimentally observed. Despite the important steps taken towards realizing novel applications, essential physics such as the diffusion constant of intercalated protons and the crystal transformation energy between VO and HVO are still lacking. In this work, we investigated the physical parameters of proton diffusion constants accompanied by VO to HVO crystal transformation with temperature variation and their transformation energies. It was found that protons could propagate several micrometers with a crystal transformation between VO and HVO. The proton diffusion speed from HVO to VO was approximately two orders higher than that from VO to HVO The long-range propagation of protons leads to the possibility of realizing novel iontronic applications and energy devices.
二氧化钒（VO₂）是一种强关联电子材料，在室温附近具有金属-绝缘体转变（MIT）。对VO₂进行离子掺杂会显著改变其输运性质和MIT温度。最近，实验观察到绝缘的氢化VO₂（HVO₂）伴随着VO₂晶体结构的转变。尽管在实现新应用方面已经迈出了重要步伐，但诸如嵌入质子的扩散常数以及VO₂和HVO₂之间的晶体转变能量等基本物理性质仍然缺乏。在这项工作中，我们研究了随着温度变化，VO₂向HVO₂晶体转变过程中质子扩散常数的物理参数及其转变能量。研究发现，质子可以在VO₂和HVO₂之间的晶体转变过程中传播数微米。从HVO₂到VO₂的质子扩散速度比从VO₂到HVO₂的质子扩散速度大约高两个数量级。质子的长程传播导致了实现新型离子电子应用和能量装置的可能性。
