A study of exchange bias in BiFeO3 core/NiFe2O4 shell nanoparticles

作者:Yusuf S M*; Manna P K; Shirolkar Mandar M; Kulkarni S K; Tewari R; Dey G K
来源:Journal of Applied Physics, 2013, 113(17): 173906.
DOI:10.1063/1.4803549

摘要

We have carried out magnetization measurements on BiFeO3 core/NiFe2O4 shell nanoparticles, and searched for the exchange bias phenomenon in this system. The core-shell nature of these nanoparticles has been established from the transmission electron microscopy images. The neutron diffraction study establishes that the core is G-type antiferromagnetic, while the shell is ferrimagnetic in nature. The search for an exchange bias phenomenon in the core-shell system shows a shift of the field-cooled (FC) hysteresis loops, at 5K, along the magnetic field axis. The present investigation shows an unusual shift of the zero field-cooled (ZFC) hysteresis loop along the magnetic field axis as well. An enhancement of the remanent magnetization along with a decrease in the coercivity is also observed in the FC case, as compared to the corresponding values in the ZFC case, which is not found commonly in any conventional exchange-biased system. All these features indicate the presence of an interface exchange coupling between core and shell of the studied nanoparticles.

  • 出版日期2013-5-7