Low cation coordination in oxide melts.
Low cation coordination in oxide melts.
复制标题
氧化物熔体中的低阳离子配位。
DOI：
10.1103/physrevlett.112.157801
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发表时间：
2014
影响因子：
8.6
通讯作者：
J. B. Parise
中科院分区：
文献类型：
--
作者：
L. Skinner;C. Benmore;J. Weber;Jincheng Du;Jörg Neuefeind;S. Tumber;J. B. Parise
在2870 K下，用气动悬浮、中子和X射线衍射相结合的方法，测量了稀土氧化物熔体的一整套部分电子对分布函数。测得这些同晶熔体的平均Y-O（或Ho-O）配位为5.5（2），这明显小于晶体Y_2O_3（或Ho_2O_3）的八面体配位。调查的La 2 O3，ZrO 2，和Al 2 O3熔体的X-射线衍射和分子动力学模拟也显示低于晶体阳离子氧配位。这些测量结果表明，与其晶体对应物相比，一般倾向于较低的配位。据发现，配位下降是较大的较低的场强，较大的半径的阳离子和高场强（网络形成）的阳离子，如二氧化硅是可以忽略不计的。这些发现对预测金属氧化物熔体和氧化物玻璃的局部结构和相关物理性质具有广泛的意义。
The complete set of partial pair distribution functions for a rare earth oxide liquid are measured by combining aerodynamic levitation, neutron and x-ray diffraction on Y2O3, and Ho2O3 melts at 2870 K. The average Y-O (or Ho-O) coordination of these isomorphic melts is measured to be 5.5(2), which is significantly less than the octahedral coordination of crystalline Y2O3 (or Ho2O3). Investigation of La2O3, ZrO2, and Al2O3 melts by x-ray diffraction and molecular dynamics simulations also show lower-than-crystal cation-oxygen coordination. These measurements suggest a general trend towards lower coordination compared to their crystalline counterparts. It is found that the coordination drop is larger for lower field strength, larger radius cations and is negligible for high field strength (network forming) cations, such as SiO2. These findings have broad implications for predicting the local structure and related physical properties of metal-oxide melts and oxide glasses.