Magnetic Core-Shell Structure and Proximity Effect in 7 nm Single-Crystal Co3O4 Nanowires

preprint2011arXivOpen access

Abstract

We present a study of magnetic properties of single-crystal Co3O4 nanowires with diameter about 7 nm. The nanowires expose (111) planes composed of plenty of Co3+ cations and exhibit two Néel temperatures at 56 K (TN of wire cores) and 73 K (TN of wire shells), which are far above TN = 40 K of bulk Co3O4. This novel bahavior is attributed to symmetry breaking of surface Co3+ cations and magnetic proximity effect. The nanowire shells show macroscopic residual magnetic moments. Cooling in a magnetic field, a fraction of the residual moments are tightly pinned to the antiferromagnetic lattice, which results in an obvious horizontal and vertical shift of hysteresis loop. Our experiment demonstrates that the exchange bias field HE and the pinned magnetic moments Mpin follow a simple expression HE = aMpin with a a constant.

Explore this paper’s authors, topics and related work.

Building this map preview

BZPEER is loading the nearby papers, people, topics and institutions for this page.

Reviews 0

Write a reviewWrite

No reviews yet.

Discussion 0

Add a commentWrite

No comments yet.