THE ATOMIC-STRUCTURE OF THE INTERFACE OF AU ON YBA2CU3O7(001)

The interface of Au films grown epitaxially on c-axis-oriented YBa2CU3 O7 has been investigated by means of high-resolution transmission elec tron microscopy and electron diffraction. Two kinds of crystallographi c orientation relationship between the two materials were identified T hese are, with respect to the parallelity of plane normals and lattice directions, as follows: ((1) over bar 11)(Au) parallel to (001)(Y), [ 110](Au) parallel to [0(1) over bar0$](Y) and [(1) over bar 1 (2) over bar](Au) parallel to [100](Y)((1) over bar 11)(Au) parallel to (001)( Y), [110](Au) parallel to [100](Y) and [112](Au) parallel to [010](Y). They can be attributed to the special bonding geometry of An atoms to Ba cations in the BaO plane which terminates the YBa2Cu3O7 at the int erface. This geometry can be understood on the basis of the atomic arr angement in the intermetallic alloy phase Au2Ba.