In:
Applied Physics Letters, AIP Publishing, Vol. 108, No. 25 ( 2016-06-20)
Abstract:
Activating ferromagnetic couplings of transition-metallic ions in the antiferromagnetic metal oxide semiconductors is desired for creating ferromagnetic semiconductors for spintronics applications. Here, we report intrinsic ferromagnetic coupling in a typical antiferromagnetic metal oxide Co3O4, by virtue of a hybrid structure that modifies the valence state of Co ions. The Co3O4 quantum dots exhibit ferromagnetism of 2.2 emu/g at 2 K after hybridization with reduced graphene oxide (RGO). In this hybrid structure, electron-transfer from RGO to Co3O4 occurs and Co3+ ions occupying the octahedral (Oh) positions are converted into Co2+. Then the super-exchange interactions between Co2+ ions at Td (tetrahedral) and Oh positions switch the magnetic coupling of Co2+(Td)–Co2+(Td) from antiferromagnetic to ferromagnetic. These results offer promise for tailoring the spin exchange interactions of oxide semiconductors for spintronics applications.
Type of Medium:
Online Resource
ISSN:
0003-6951
,
1077-3118
Language:
English
Publisher:
AIP Publishing
Publication Date:
2016
detail.hit.zdb_id:
211245-0
detail.hit.zdb_id:
1469436-0
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