Hiroi Z, Horiuchi S
Institute for Chemical Research, Kyoto University, Japan.
Microsc Res Tech. 1998 Feb 15;40(4):251-64. doi: 10.1002/(SICI)1097-0029(19980215)40:4<251::AID-JEMT2>3.0.CO;2-V.
Two families of alkaline-earth copper oxides are studied by using high-voltage high-resolution electron microscopy. One is Sr(n-1) Cu(n)O(2n-1) (n = 2, 3), the so-called spin-ladder compounds, and the other is ACuO2 (A = Ca-Sr) crystallizing in the infinite-layer structure, which is a parent structure for all copper oxide superconductors. It is demonstrated in the former compounds that oxygen columns as well as metal columns are directly imaged in a "structure" image. Moreover, twin-related lattice defects, which can be the origin of free Cu2+ spins observed previously in magnetic measurements, have been detected in SrCu2O3. An interesting irradiation effect under a 1,000-kV electron beam has been observed in the infinite-layer compound: An unusual structural phase transformation to a NaCl-type lattice is induced, accompanied by the formation of nm-size twin domains.
利用高压高分辨电子显微镜对两类碱土铜氧化物进行了研究。一类是Sr(n - 1)Cu(n)O(2n - 1)（n = 2, 3），即所谓的自旋梯子化合物，另一类是结晶为无限层结构的ACuO2（A = Ca - Sr），它是所有铜氧化物超导体的母体结构。在前一类化合物中，在“结构”图像中直接成像了氧柱以及金属柱。此外，在SrCu2O3中检测到了孪晶相关的晶格缺陷，这可能是先前在磁性测量中观察到的自由Cu2+自旋的起源。在无限层化合物中观察到了在1000 kV电子束下的一种有趣的辐照效应：诱导了向NaCl型晶格的异常结构相变，并伴随着纳米尺寸孪晶畴的形成。
