Enhanced magnetic anisotropy in cobalt-carbide nanoparticles

Journal Article · Mon Jan 13 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4862260· OSTI ID:1211328

El-Gendy, AA; Qian, MC; Huba, ZJ; Khanna, SN; Carpenter, EE

An outstanding problem in nano-magnetism is to stabilize the magnetic order in nanoparticles at room temperatures. For ordinary ferromagnetic materials, reduction in size leads to a decrease in the magnetic anisotropy resulting in superparamagnetic relaxations at nanoscopic sizes. In this work, we demonstrate that using wet chemical synthesis, it is possible to stabilize cobalt carbide nanoparticles which have blocking temperatures exceeding 570 K even for particles with magnetic domains of 8 nm. First principles theoretical investigations show that the observed behavior is rooted in the giant magnetocrystalline anisotropies due to controlled mixing between C p- and Co d-states. (C) 2014 AIP Publishing LLC.

• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• DOE Contract Number: 1574-1674
• OSTI ID: 1211328
• Journal Information: Applied Physics Letters, Vol. 104, Issue 2; ISSN 0003-6951
• Country of Publication: United States
• Language: English