Physica C 218 (1993) 501-504 North-Holland PHYSICA

Errata

Direct imaging of the oxygen sublattice in thin crystals of orthorhombic YBa2Cu307_x superconductors observed by HREM at 400 kV

Y. Yan and M.G. Blanchin

Physica C 198 (1992) 147-161

Due to an administrative error made by the publisher the original, unrevised version o f this paper was pub- lished. On page 148 the last part o f sect. 1 (upper part o f right-hand co lumn) should read:

and thus the oxygen sublattice was directly visual- ized [ 12,13 ]. Recently, Horiuchi et al. have also suc- ceeded in imaging directly oxygen atoms in a tetrag- onal YBa2Cu307 +~ crystal as well as in zirconia ZrO2

[19-21 ] using a new high-resolution electron mi- croscope operated at a much higher voltage ( 8 0 0 - 1000 kV) [22] . The present study concerns the vis- ibility of the oxygen sublattice in YBa2Cu3OT_~ su-

PG [100] PG [010]

Fig. 4. (a) Enlargement of a high magnification micrograph along the [ 100] direction, together with the projected potential of the structure; inset is the simulated image (crystal thickness t= 1 rim, Af= -48 nm). (b) Enlargement of a high magnification micrograph along the [ 010 ] direction, together with the projected potential of the structure; inset is the simulated image (crystal thickness t = 1.4 nm, Af= -48 nm).

0921-4534/93/$06.00 @ 1993 Elsevier Science Publishers B.V. All fights reserved.

502 Errata

Fig. 10. Enlargement of a HREM image along the [ 100 ] direction; inset is the simulated image (crystal thickness t = 1.9 nm, A f= - 46 nm). The contrast of the oxygen atoms in the image is emphasized by dynamical scattering effects.

perconductors imaged by means of HREM micros- copy at 400 kV, which corresponds to a far more common type of microscope. In the present paper, HREM images at 400 kV from very th in regions of a YBa2Cu307_x specimen are studied systematically, the dependence of the HREM image contrast on dif- ferent factors being discussed through comparison of experimental images with simulated images and structural models.

References

[19]S. Horiuchi, Y. Matsui, Y. Kitami, M. Yokoyama, S. Suehara, X.J. Wu, I. Matsui and T. Katsuta, Ultramicroscopy 39 ( 1991 ) 231.

[20] S. Horiuchi, Y. Matsui and B. Okai, Jpn. J. Appl. Phys. 31 (1992) L59.

[ 21 ] S. Horiuchi, Y. Matsui, Jpn. J. Appl. Phys. 31 ( 1992 ) L283. [22] Y. Matsui, S. Horiuchi, Y. Bando, Y. Kitami, M. Yokoyama,

S. Suehara, I. Matsui and T. Katsuta, Ultramicroscopy 39 (1991) 8.

Further, figs. 4 and 10 were badly reproduced and are reprinted here.