XMCD and XMCD‐PEEM Studies on Magnetic‐Field‐Assisted Self‐Assembled 1D Nanochains of Spherical Ferrite Particles. (30th May 2017)

• Record Type: Journal Article
• Authors: Zhang, Wen; Wong, Ping Kwan Johnny; Zhang, Dong; Yue, Jinjin; Kou, Zhaoxia; van der Laan, Gerrit; Scholl, Andreas; Zheng, Jian‐Guo; Lu, Zuhong; Zhai, Ya
• Is Part Of: Advanced functional materials. Volume 27:Number 29(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-05-30
• Subjects: 1D nanochains -- cation distribution -- ferrites -- magnetic properties -- X‐ray magnetic circular dichroism (XMCD); Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201701265
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract : Quasi‐1D nanochains of spherical magnetic ferrite particles with a homogeneous particle size of ≈200 nm and a micrometer‐sized chain length are fabricated via a self‐assembly method under an external magnetic field. This assisting magnetic field ( H assist ), applied during synthesis, significantly modifies the distribution of the Fe 2+ Oh, Fe 3+ Td, and Fe 3+ Oh cations in the chains, as demonstrated by X‐ray magnetic circular dichroism (XMCD) combined with theoretical analysis. This provides direct evidence of the nontrivial role of external synthetic conditions for defining the crystal chemistry of nanoscale ferrites and in turn their magnetic properties, providing an extra degree of freedom for intentional control over the performances of 1D magnetic nanodevices for various applications. Magnetic imaging, performed via XMCD in photoemission electron microscopy, further shows the possibility of creating and trapping a series of adjacent magnetic domain walls in a single chain, suggesting that there is great application potential for these nanochains in 1D magnetic nanodevices, as determined by field‐ or current‐driven domain wall motions. Practical control over the magnetic properties of the nanochains is also achieved by extrinsic dopants of cobalt and zinc, which are observed to occupy the ferrite ionic sites in a selective manner. Abstract : Magnetic‐field‐assisted self‐assembled 1D nanochains of spherical ferrite particles are investigated using X‐ray magnetic circular dichroism (XMCD), revealing the important role of H assist in determining the magnetic properties of nanoscale ferrites. An assisting magnetic field during synthesis ( H assist ) of 2500 Oe offers a favorable fabrication condition for obtaining suitable nanochains for applications in magnetic 1D nanodevices, and the first observation on the precise pinning of domain walls is achieved via XMCD in photoemission electron microscopy (PEEM).