Interfacial Ferromagnetism in LaNiO3/CaMnO3 Superlattices

Published

August 21, 2013

Author(s)

A. J. Grutter, H. Yang, Brian Kirby, M. R. Fitzsimmons, J. A. Aguiar, N. D. Browning, C. A. Jenkins, E. Arenholz, V. V. Mehta, U. S. Alaan, Y. Suzuki

Abstract

We observe interfacial ferromagnetism in superlattices of the paramagnetic metal LaNiO₃ and the antiferromagnetic insulator CaMnO₃. The magnetic behavior can be explained in terms of an interfacial double exchange mechanism in which itinerant electrons from the LaNiO₃ layer mediate canted ferromagnetism in the CaMnO₃ layer. After varying the thickness of the LaNiO₃; which undergoes a thickness dependent, metal-insulator transition, we found the emergence of ferromagnetism to be coincident with the conducting state of LaNiO₃. That is, only superlattices in which the LaNiO₃ layers are metallic exhibit ferromagnetism. Through a combination of SQUID magnetometry, X-ray magnetic circular dichroism, and polarized neutron reflectometry, we have probed the magnetic behavior and determined that the FM arises in a single unit cell of CaMnO₃ at the interface. Together those results suggest that ferromagnetism can be attributed to a double exchange interaction among Mn ions mediated by the adjacent itinerant metal.

Citation

Physical Review Letters

Volume

111

Issue

8

Pub Type

Journals

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Keywords

PNR, magnetism

Citation

Grutter, A. , Yang, H. , Kirby, B. , Fitzsimmons, M. , Aguiar, J. , Browning, N. , Jenkins, C. , Arenholz, E. , Mehta, V. , Alaan, U. and Suzuki, Y. (2013), Interfacial Ferromagnetism in LaNiO₃/CaMnO₃ Superlattices, Physical Review Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=913492 (Accessed September 10, 2024)