Interface Induced Antiferromagnetism in High-Tc/Manganite

N. HABERKORN; J. GUIMPEL; W. SALDARRIAGA; E. BACA; M.E. GÓMEZ; L. CIVALE

Los Angeles

Congreso; APS March Meeting; 2005

American Physical Society

We study the magnetic properties of perovskite based superconducting High-Tc / ferromagnetic manganite superlattices. The zero field cooled hysteresis loops show the expected ferromagnetic behaviour. However, field cooled low temperature hysteresis loops show the unexpected presence of exchange bias, signature of the existence of ferromagnetic/antiferromagnetic (F/AF) interfaces. The origin of the AF material is probably associated to interface disorder and Mn valence shift towards Mn^4+. The blocking temperature is found thickness dependent and the exchange bias field is found inversely proportional to the F layer thickness, as expected.