Antiferromagnetism at the YBa2 Cu3 O7/ La2/3Ca1/3MnO3 interface

N. HABERKORN, J. GUIMPEL,M. SIRENA, L. B. STEREN,W. SALDARRIAGA, E. BACA, M. E. GOMEZ

APPLIED PHYSICS LETTERS

American Institute of Physics

Lugar: New York; Año: 2004 vol. 84 p. 3927 - 3929

0003-6951

The magnetic properties of a series of YBa 2 Cu 3 O 72x /La 2/3 Ca 1/3 MnO 3 (YBCO/LC 1/3 MO) superlattices grown by dc sputtering at high oxygen pressures ~3.5 mbar! show the expected ferromagnetic behavior. However, field-cooled hysteresis loops at a low temperatures show the unexpected existence of exchange bias effect associated with the existence of ferromagnetic/ antiferromagnetic ~AF! interfaces. The blocking temperature (T B ) is found to be thickness dependent and the exchange bias field (H EB ) is found to be inversely proportional to the ferromagnetic layer thickness, as expected. The presence of an AF material is probably associated with interface disorder and Mn valence shift toward Mn 41  2 Cu 3 O 72x /La 2/3 Ca 1/3 MnO 3 (YBCO/LC 1/3 MO) superlattices grown by dc sputtering at high oxygen pressures ~3.5 mbar! show the expected ferromagnetic behavior. However, field-cooled hysteresis loops at a low temperatures show the unexpected existence of exchange bias effect associated with the existence of ferromagnetic/ antiferromagnetic ~AF! interfaces. The blocking temperature (T B ) is found to be thickness dependent and the exchange bias field (H EB ) is found to be inversely proportional to the ferromagnetic layer thickness, as expected. The presence of an AF material is probably associated with interface disorder and Mn valence shift toward Mn 41