Delta doping of ferromagnetism in antiferromagnetic manganite superlattices.

Journal Article · Sat Jan 01 04:00:00 EST 2011 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.107.167202· OSTI ID:1028617

Santos, T S; Kirby, B J; Kumar, S; May, S J; Borchers, J A; Maranville, B B; Zarestky, J; van den Brink, J; Bhattacharya, A ^[1]

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1. Center for Nanoscale Materials

We demonstrate that delta doping can be used to create a dimensionally confined region of metallic ferromagnetism in an antiferromagnetic (AFM) manganite host, without introducing any explicit disorder due to dopants or frustration of spins. Theoretical consideration of these additional carriers shows that they cause a local enhancement of ferromagnetic double exchange with respect to AFM superexchange, resulting in local canting of the AFM spins. This leads to a highly modulated magnetization, as measured by polarized neutron reflectometry. The spatial modulation of the canting is related to the spreading of charge from the doped layer and establishes a fundamental length scale for charge transfer, transformation of orbital occupancy, and magnetic order in these manganites. Furthermore, we confirm the existence of the canted, AFM state as was predicted by de Gennes [Phys. Rev. 118 141 (1960)] but had remained elusive.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1028617
• Report Number(s): ANL/MSD/JA-71118
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 16 Vol. 107; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETIC MATERIALS
ATOMIC FORCE MICROSCOPY
DOPED MATERIALS
EXCHANGE INTERACTIONS
FERROMAGNETISM
LAYERS
LENGTH
MAGNETIC PROPERTIES
MAGNETIZATION
MANGANATES
MODULATION
SUPERLATTICES
TRANSFORMATIONS