FLUORINATION OF YBA2CU3O6.7 - POWDER NEUTRON-DIFFRACTION DETERMINATION OF FLUORINE SITES AND THEIR INFLUENCE ON THE SUPERCONDUCTING PROPERTIES

被引：50

作者：

PERRIN, C ^{[1
]}

DINIA, A ^{[1
]}

PENA, O ^{[1
]}

SERGENT, M ^{[1
]}

BURLET, P ^{[1
]}

ROSSATMIGNOD, J ^{[1
]}

机构：

[1] CEN,DRF,SPH MDN,F-38041 GRENOBLE,FRANCE

来源：

SOLID STATE COMMUNICATIONS | 1990年 / 76卷 / 03期

关键词：

D O I：

10.1016/0038-1098(90)90863-7

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

The crystal structures of YBa2Cu3O6.7 before and after 30 minutes or 75 minutes of fluorination under diluted NF3 at 300°C, were determined by powder neutron diffraction experiments. For short time of fluorination, the occupancy of the (0, 1 28:48 AM 6/6/02, 0) site increases while the one of the ( 1 2, 0, 0) position does not vary too much. For higher fluorine concentration, the (0, 1 2, 0) occupancy seems to reach a limit, while the ( 1 2, 0, 0) one further increases. These structural results are discussed in relation with the two different evolutions of the superconducting behaviour previously observed : the enhancement of Tc from 65 K upto 90 K is related to the occupancy of the 0 (4) sites in the CuO chains along the b axis, while filling the 0(5) sites along the a axis mainly affects the a.c. susceptibility amplitude which decreases suddenly from 100% down to about 30%. © 1990.

引用

页码：401 / 407

页数：7