HIGH-RESOLUTION STM STS STUDIES OF DOPING EFFECTS ON BI-O LAYERS IN BI-2122 HIGH-TC CUPRATE

被引:19
作者
SAMANTA, SB
DUTTA, PK
AWANA, VPS
NARLIKAR, AV
机构
[1] National Physical Laboratory, New Delhi 12, Dr. K. S. Krishnan Road
来源
EUROPHYSICS LETTERS | 1991年 / 16卷 / 04期
关键词
D O I
10.1209/0295-5075/16/4/013
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
Effects arising from the presence of excess oxygen in the Bi-O layer of Bi-2122 compound have been studied with the STM/STS technique which has been effectively used for obtaining atomically resolved images. The excess oxygen is incorporated by substituting Dy3+ at the Ca2+-site as well as by oxygenating the pure sample. It has been possible to detect and directly observe the excess oxygen atoms in the Bi-O layer which is in accord with the information inferred from neutron diffraction and HRTEM studies of other workers. The controversial issue of whether the Bi-O layer is conducting or insulating has been discussed in the light of the SIS findings on doped samples. The results show that there is a gradual increase in its room temperature gap and a decrease in the LDOS, indicating the Bi-O layer to become insulating with incorporation of excess oxygen.
引用
收藏
页码:391 / 396
页数:6
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