Please use this identifier to cite or link to this item: http://dspace.library.iitb.ac.in/xmlui/handle/123456789/20982
Title: Exchange Bias Induced by the Spin Glass-Like Surface Spins in Sputter Deposited Fe3O4 Thin Films
Authors: SHAMEEM, PVM
MEKALA, L
KUMAR, MS
Keywords: Magnetite
Issue Date: 2017
Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Citation: IEEE TRANSACTIONS ON MAGNETICS,53(11)
Abstract: The exchange bias in the reactive sputtered polycrystalline Fe3O4 thin films of thicknesses 50 and 150 nm is studied. X-ray diffraction, laser Raman, and selected area electron diffraction studies confirm the formation of the Fe3O4 single phase. The high-resolution transmission electron microscope images show the presence of well-defined crystallites. The presence of the exchange bias effect is mainly due to the existence of a significant exchange coupling between the core spins and the spin glass-like surface spins of the grains. The temperature dependence of the magnitude of the exchange bias field HEB shows two exponential regimes of which the lower temperature regime corresponds to the spin freezing effect below 50 K. The first magnetization curves measured after zero field cooling show S-shape below the spin freezing temperature. The presence of superparamagnetism and spin freezing has been investigated through the field cooled (FC) and zero FC magnetization measurements. Temperature dependence of coercivity also indicates the spin freezing effect. Hence, the observed large exchange bias of the samples at lower temperatures is due to the freezing of the surface spins.
URI: http://dx.doi.org/10.1109/TMAG.2017.2703884
http://localhost:8080/xmlui/handle/123456789/20982
ISSN: 0018-9464
1941-0069
Appears in Collections:Article

Files in This Item:
There are no files associated with this item.


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.