Transient shift of local oxygen potential in nonstoichiometric oxides upon application of mechanical stress
Transient shift of local oxygen potential in nonstoichiometric oxides upon application of mechanical stress
复制标题
施加机械应力时非化学计量氧化物中局部氧势的瞬态变化
DOI：
10.1007/s10832-013-9885-x
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Koji Amezawa
中科院分区：
文献类型：
--
作者：
Tatsuya Kawada;Tomohisa Masumitsu. Yuta Kimura;Satoshi Watanabe;Shin-ichi Hashimoto;Keiji Yashiro;Koji Amezawa
研究了机械应力对氧非化学计量比化合物La_（0.6）Sr_（0.4）Co_（0.2）Fe_（0.8）O_（3-δ）缺陷平衡的影响。通常，氧化物中的氧空位的形成引起晶格膨胀，这导致在拉伸应力下材料中的氧空位的稳定化，反之亦然。因此，在拉伸应力下氧空位浓度增加，在压缩应力下氧空位浓度降低。然而，缺陷浓度的变化不会自发地进行，因此在施加应力之后材料将保持不平衡。在此假设下，尝试使用电位法检测在应力下氧电位的变化。利用直径为9.5 mm的球形氧化钇稳定的氧化锆（YSZ）作为氧势传感器以及压在样品表面上的推杆。在873 K至1073 K的测量中，观察到电动势明显向负方向移动，这取决于负载的大小和加载速度。在应力作用下，材料的应力松弛到初始值。在卸载操作时，电动势的正向移动被观察到。这些行为很好地解释了假设的氧空位浓度变化的机械应力。
Effect of mechanical stress on defect equilibrium was studied with an oxygen nonstoichiometric compound, La0.6Sr0.4Co0.2Fe0.8O3-δ. In general, formation of oxygen vacancy in an oxide causes lattice expansion, which leads to stabilization of oxygen vacancy in the material under a tensile stress, and vice versa. Oxygen vacancy concentration is thus expected to increase under a tensile stress and decrease under a compressive stress. However, the change in defect concentration would not proceed spontaneously so that the material just after the application of stress would stay out of equilibrium. On this assumption, attempts were made to detect the shift of oxygen potential under stress using a potentiometric method. A ball-shaped yttria stabilized zirconia (YSZ) of 9.5 mm in diameter was utilized as an oxygen potential sensor as well as a pushing rod which was pressed onto the sample surface. In the measurements at 873 K to 1073 K, a clear shift of emf to the negative direction was observed depending on the magnitude of load and loading speed. It was followed by a relaxation to the initial value under the stress. On unloading operation, the shift of emf to the positive direction was observed. Those behaviors were well explained by the assumption that the oxygen vacancy concentration varies under mechanical stress.
DOI：
10.1002/bbpc.198700011
发表时间：
1987
期刊：
影响因子：
--
作者：
W. Durham;H. Schmalzried
通讯作者：
H. Schmalzried
DOI：
--
发表时间：
1963
期刊：
影响因子：
--
作者：
R. Coble;Y. Guérard
通讯作者：
Y. Guérard
测量高温下施加到离子材料界面的正应力引起的电势
影响因子：
9.4
作者：
A. Pannikkat;R. Raj
通讯作者：
R. Raj