Exchange bias and Verwey transition in Fe5C2/Fe3O4 core/shell nanoparticles. Issue 37 (14th September 2021)

• Record Type: Journal Article
• Authors: Xing, M.; Mohapatra, Jeotikanta; Elkins, J.; Guragain, D.; Mishra, S. R.; Ping Liu, J.
• Is Part Of: Nanoscale. Volume 13:Issue 37(2021)
• Page Start: 15837
• Page End: 15843
• Publication Date: 2021-09-14
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d1nr04520b
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : This report presents new findings of exchange bias and related structural and magnetic properties in iron carbide/magnetite (Fe5 C2 /Fe3 O4 ) core/shell nanoparticles. Abstract : This report presents new findings of exchange bias and related structural and magnetic properties in iron carbide/magnetite (Fe5 C2 /Fe3 O4 ) core/shell nanoparticles. The exchange bias emerges from an energetic landscape, namely a first-order phase transition–the Verwey transition at 125 K, during which the Fe3 O4 shell changes from the cubic to monoclinic structure. The phase transition leads to the exchange bias because it results in abrupt changes in magnetocrystalline anisotropy and exchange coupling. Another unique phenomenon identified in this composite system is enhanced magnetic coercivity due to the uniaxial anisotropy of the monoclinic phase. An analysis of the correlations between the observed phenomena is given based on the temperature dependence of the coercivity, the exchange bias field values, and the Verwey transition temperature.