Hashimoto Hideki, Onodera Yohei, Tahara Shuta, Kohara Shinji, Yazawa Koji, Segawa Hiroyo, Murakami Motohiko, Ohara Koji
Department of Applied Chemistry, School of Advanced Engineering, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo, 192-0015, Japan.
Institute for Integrated Radiation and Nuclear Science, Kyoto University, 2-1010 Asashiro-nishi, Kumatori-cho, Sennan-gun, Osaka, 590-0494, Japan.
Sci Rep. 2022 Jan 11;12(1):516. doi: 10.1038/s41598-021-04455-6.
The fabrication of novel oxide glass is a challenging topic in glass science. Alumina (AlO) glass cannot be fabricated by a conventional melt-quenching method, since AlO is not a glass former. We found that amorphous AlO synthesized by the electrochemical anodization of aluminum metal shows a glass transition. The neutron diffraction pattern of the glass exhibits an extremely sharp diffraction peak owing to the significantly dense packing of oxygen atoms. Structural modeling based on X-ray/neutron diffraction and NMR data suggests that the average Al-O coordination number is 4.66 and confirms the formation of OAl triclusters associated with the large contribution of edge-sharing Al-O polyhedra. The formation of edge-sharing AlO and AlO polyhedra is completely outside of the corner-sharing tetrahedra motif in Zachariasen's conventional glass formation concept. We show that the electrochemical anodization method leads to a new path for fabricating novel single-component oxide glasses.
新型氧化物玻璃的制备是玻璃科学中一个具有挑战性的课题。氧化铝（AlO）玻璃不能通过传统的熔体淬火法制备，因为AlO不是玻璃形成体。我们发现，通过铝金属的电化学阳极氧化合成的非晶态AlO表现出玻璃转变。该玻璃的中子衍射图谱由于氧原子的显著密集堆积而呈现出一个极其尖锐的衍射峰。基于X射线/中子衍射和核磁共振数据的结构建模表明，平均Al-O配位数为4.66，并证实了与边共享Al-O多面体的巨大贡献相关的OAl三聚体的形成。边共享AlO和AlO多面体的形成完全超出了扎卡里亚森传统玻璃形成概念中的角共享四面体模式。我们表明，电化学阳极氧化法为制备新型单组分氧化物玻璃开辟了一条新途径。
