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Synthesis and Characteristics of FePt Nanoparticle Films Under In Situ-Applied Magnetic Field.

Qian X, Gao MY, Li AD, Zhou XY, Liu XJ, Cao YQ, Li C, Wu D - Nanoscale Res Lett (2016)

Bottom Line: The effect of in situ-applied magnetic field on the structure, morphology, and magnetic properties of FePt nanoparticle films was characterized.It is found that the applied magnetic field during the chemical synthesis of FePt nanoparticles plays a key role in the crystallinity and magnetic property of FePt nanoparticle films.The applied magnetic field during the synthesis of FePt nanoparticles not only significantly improves the nanoparticles' c-axis preferred orientation but also benefits the phase transition of FePt nanoparticles from face-centered cubic to face-centered tetragonal structure during the annealing process.

View Article: PubMed Central - PubMed

Affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, People's Republic of China.

ABSTRACT
In situ external magnetic field was applied during the synthesis of FePt nanoparticles via a chemical solution method. FePt nanoparticle films were prepared on Si by a drop-coating method with and without a magnetic field. Annealing at 700 °C in reductive atmosphere was explored to obtain ferromagnetic FePt L10 phase. The effect of in situ-applied magnetic field on the structure, morphology, and magnetic properties of FePt nanoparticle films was characterized. It is found that the applied magnetic field during the chemical synthesis of FePt nanoparticles plays a key role in the crystallinity and magnetic property of FePt nanoparticle films. As-synthesized FePt nanoparticles under the magnetic field are monodispersed and can be self-assembled over a larger area by a dropping method. The applied magnetic field during the synthesis of FePt nanoparticles not only significantly improves the nanoparticles' c-axis preferred orientation but also benefits the phase transition of FePt nanoparticles from face-centered cubic to face-centered tetragonal structure during the annealing process. The FePt nanoparticle films derived under magnetic field also show some magnetic anisotropy.

No MeSH data available.


The hysteresis loops of FePt nanoparticle films for the 2# (a, b) and 3# (c, d) samples. The applied magnetic field during measuring is perpendicular to the film with denotation of H⊥ and parallel to the film with H∥
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Fig5: The hysteresis loops of FePt nanoparticle films for the 2# (a, b) and 3# (c, d) samples. The applied magnetic field during measuring is perpendicular to the film with denotation of H⊥ and parallel to the film with H∥

Mentions: The FePt nanoparticle films synthesized under magnetic field also show some magnetic anisotropy which was characterized by SQUID after 700 °C annealing. The in-plane coercivity and out-plane coercivity are represented with Hc,∥ and Hc,⊥, respectively. The ratio value (h) of Hc,∥/Hc,⊥ can be used to determine the orientation degree of magnetic moments (M). If h = 1, it means that the fct-FePt nanoparticle films are completely random oriented; h > 1, the M is in-plane oriented; h < 1, the M is out-of-plane oriented. Figure 5 plots the hysteresis loops of the 2# and 3# samples measured under an applied magnetic field parallel to or perpendicular to the films. The annealed 2# sample with an applied magnetic field during chemical synthesis and without a magnetic field during drop-coating has the Hc,∥ and Hc,⊥ of 17.8 and 16.2 kOe with a remanence ratio of 0.89 and 0.82, respectively. The h value of 1.10 indicates some degree of in-plane oriented. Correspondingly, the annealed 3# sample with an applied magnetic field during chemical synthesis and drop-coating has the Hc,∥ and Hc,⊥ of 10.2 and 9.8 kOe with remanence ratio of 0.84 and 0.682, respectively. The calculated h value of 1.04 also shows slight in-plane oriented. That is to say, the in-plane coercivity and corresponding remanence ratio are larger than the out-of-plane ones.Fig. 5


Synthesis and Characteristics of FePt Nanoparticle Films Under In Situ-Applied Magnetic Field.

Qian X, Gao MY, Li AD, Zhou XY, Liu XJ, Cao YQ, Li C, Wu D - Nanoscale Res Lett (2016)

The hysteresis loops of FePt nanoparticle films for the 2# (a, b) and 3# (c, d) samples. The applied magnetic field during measuring is perpendicular to the film with denotation of H⊥ and parallel to the film with H∥
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940308&req=5

Fig5: The hysteresis loops of FePt nanoparticle films for the 2# (a, b) and 3# (c, d) samples. The applied magnetic field during measuring is perpendicular to the film with denotation of H⊥ and parallel to the film with H∥
Mentions: The FePt nanoparticle films synthesized under magnetic field also show some magnetic anisotropy which was characterized by SQUID after 700 °C annealing. The in-plane coercivity and out-plane coercivity are represented with Hc,∥ and Hc,⊥, respectively. The ratio value (h) of Hc,∥/Hc,⊥ can be used to determine the orientation degree of magnetic moments (M). If h = 1, it means that the fct-FePt nanoparticle films are completely random oriented; h > 1, the M is in-plane oriented; h < 1, the M is out-of-plane oriented. Figure 5 plots the hysteresis loops of the 2# and 3# samples measured under an applied magnetic field parallel to or perpendicular to the films. The annealed 2# sample with an applied magnetic field during chemical synthesis and without a magnetic field during drop-coating has the Hc,∥ and Hc,⊥ of 17.8 and 16.2 kOe with a remanence ratio of 0.89 and 0.82, respectively. The h value of 1.10 indicates some degree of in-plane oriented. Correspondingly, the annealed 3# sample with an applied magnetic field during chemical synthesis and drop-coating has the Hc,∥ and Hc,⊥ of 10.2 and 9.8 kOe with remanence ratio of 0.84 and 0.682, respectively. The calculated h value of 1.04 also shows slight in-plane oriented. That is to say, the in-plane coercivity and corresponding remanence ratio are larger than the out-of-plane ones.Fig. 5

Bottom Line: The effect of in situ-applied magnetic field on the structure, morphology, and magnetic properties of FePt nanoparticle films was characterized.It is found that the applied magnetic field during the chemical synthesis of FePt nanoparticles plays a key role in the crystallinity and magnetic property of FePt nanoparticle films.The applied magnetic field during the synthesis of FePt nanoparticles not only significantly improves the nanoparticles' c-axis preferred orientation but also benefits the phase transition of FePt nanoparticles from face-centered cubic to face-centered tetragonal structure during the annealing process.

View Article: PubMed Central - PubMed

Affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, People's Republic of China.

ABSTRACT
In situ external magnetic field was applied during the synthesis of FePt nanoparticles via a chemical solution method. FePt nanoparticle films were prepared on Si by a drop-coating method with and without a magnetic field. Annealing at 700 °C in reductive atmosphere was explored to obtain ferromagnetic FePt L10 phase. The effect of in situ-applied magnetic field on the structure, morphology, and magnetic properties of FePt nanoparticle films was characterized. It is found that the applied magnetic field during the chemical synthesis of FePt nanoparticles plays a key role in the crystallinity and magnetic property of FePt nanoparticle films. As-synthesized FePt nanoparticles under the magnetic field are monodispersed and can be self-assembled over a larger area by a dropping method. The applied magnetic field during the synthesis of FePt nanoparticles not only significantly improves the nanoparticles' c-axis preferred orientation but also benefits the phase transition of FePt nanoparticles from face-centered cubic to face-centered tetragonal structure during the annealing process. The FePt nanoparticle films derived under magnetic field also show some magnetic anisotropy.

No MeSH data available.