Document Type
Article
Source Publication Title
Applied Physics Letters
Abstract
Chemically ordered FePt nanoparticles were obtained by high temperature annealing a mixture of FePt particles with NaCl. After the NaCl was removed with de-ionized water, the transformed FePt nanoparticles were redispersed in cyclohexanone. X-ray diffraction patterns clearly show the L10 phase. Scherrer analysis indicates that the average particle size is about 8 nm, which is close to the transmission electron microscopy (TEM) statistical results. The coercivity ranges from 16 kOe to more than 34 kOe from room temperature down to 10 K. High resolution TEM images reveal that most of the FePt particles were fully transformed into the L10 phase, except for a small fraction of particles which were partially chemically ordered. Nano-energy dispersive spectroscopy measurements on the individual particles show that the composition of the fully transformed particles is close to 50/50, while the composition of the partially transformed particles is far from equiatomic. TEM images and electron diffraction patterns indicate c-axis alignment for a monolayer of L10 FePt particles formed by drying a dilute dispersion on copper grids under a magnetic field. For thick samples dried under a magnetic field, the degree of easy axis alignment is not as high as predicted due to strong interactions between particles.
Disciplines
Physical Sciences and Mathematics | Physics
Publication Date
1-1-2009
Language
English
License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.
Recommended Citation
Nandwana, Vikas; Kang, Shishou; Shi, Shifan; Jia, Zhiyong; Thompson, G. R.; Nikles, David E.; Harrell, J. W.; Poudyal, Narayan; and Liu, J. Ping, "Microstructures and magnetic alignment of L10 FePt nanoparticles" (2009). Physics Faculty Publications. 31.
https://mavmatrix.uta.edu/physics_facpubs/31