Shi Caijuan, Alderman Oliver L G, Tamalonis Anthony, Weber J K R, Benmore Chris J
Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK.
Philos Trans A Math Phys Eng Sci. 2023 Oct 16;381(2258):20220352. doi: 10.1098/rsta.2022.0352. Epub 2023 Aug 28.
Laser-heated melts based on the 43CaO-57FeO eutectic, close to the calcium ferrite (CF) composition, were measured with high-energy X-ray diffraction using aerodynamic levitation over a range of redox states controlled by CO/CO gas atmospheres. The iron-oxygen coordination number was found to rise from 4.4 ± 0.3 at 15% Fe to 5.3 ± 0.3 at 87% Fe. Empirical potential structure refinement modelling was used to obtain the ferric and ferrous partial pair distribution functions. It was found that the Fe iron-oxygen coordination number is consistently approximately 10% higher in CF than in pure iron oxide, while Fe is essentially identical in all but the most oxygen-rich environments (where it is higher in CF compared with FeO). The model also shows calcium octahedra to be the dominant species across all redox environments, although the population of CaO increases with the availability of oxygen at the expense of CaO and CaO. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 1)'.
基于接近铁酸钙（CF）成分的43CaO - 57FeO共晶的激光加热熔体，在由CO/CO₂气体气氛控制的一系列氧化还原状态下，使用气动悬浮通过高能X射线衍射进行测量。发现铁 - 氧配位数从15%Fe时的4.4±0.3增加到87%Fe时的5.3±0.3。使用经验势结构精修模型获得铁离子和亚铁离子的部分对分布函数。发现CF中Fe的铁 - 氧配位数始终比纯氧化铁中高约10%，而除了氧含量最高的环境外（在该环境中CF中的Fe比FeO中的高），Fe基本相同。该模型还表明，在所有氧化还原环境中，钙八面体都是主要物种，尽管CaO的数量随着氧的可用性增加，以CaO和CaO为代价。本文是主题为“探索具有挑战性材料的长度尺度、时间尺度和化学性质（第1部分）”的一部分。
