Interface Induced Antiferromagnetism in High-Tc/Manganite Superlattices

ORAL

Abstract

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.

*Work partially supported by ANPCyT PICT99-6340, Fundaci\'on Balseiro, and Fundaci\'on Antorchas, Argentina

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Authors

  • N. Haberkorn

    • Universidad Nacional del Sur, Bah\'{i}a Blanca, 8000 Bs.As., Argentina and Centro At\'omico Bariloche, S. C. de Bariloche, 8400 R. N., Argentina

  • J. Guimpel

    • Centro At\'omico Bariloche, S. C. de Bariloche, 8400 R. N., Argentina

  • W. Saldarriaga

  • E. Baca

  • M.E. G\'omez

    • Departamento de F\'{i}sica, Universidad del Valle A. A.,25360 Cali, Colombia

  • L. Civale

    • Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, NM 87545 USA