Characterization of superpararnagnetic "core-shell" nanoparticles and monitoring their anisotropic phase transition to ferromagnetic "solid solution" nanoalloyse

被引:166
作者
Park, JI
Kim, MG
Jun, YW
Lee, JS
Lee, WR
Cheon, J [1 ]
机构
[1] Korea Adv Inst Sci & Technol, Dept Chem, Taejon 305701, South Korea
[2] Pohang Univ Sci & Technol, PAL, Pohang 790784, South Korea
[3] Pohang Univ Sci & Technol, Dept Chem Engn, Pohang 790784, South Korea
[4] Yonsei Univ, Dept Chem, Seoul 120749, South Korea
关键词
D O I
10.1021/ja049649k
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The structure, magnetism, and phase transition of core-shell type CoPt nanoparticles en route to solid solution alloy nanostructures are systematically investigated. The characterization of CocorePtshell nanoparticles obtained by a "redox transmetalation" process by transmission electron microscopy (TEM) and, in particular, X-ray absorption spectroscopy (XAS) provides clear evidence for the existence of a core-shell type bimetallic interfacial structure. Nanoscale phase transitions of the CocorePtshell structures toward c-axis compressed face-centered tetragonal (fct) solid solution alloy CoPt nanoparticles are monitored at various stages of a thermally induced annealing process and the obtained fct nanoalloys show a large enhancement of their magnetic properties with ferromagnetism. The relationship between the nanostructures and their magnetic properties is in part elucidated through the use of XAS as a critical analytical tool.
引用
收藏
页码:9072 / 9078
页数:7
相关论文
共 45 条
  • [1] Less is more in medicine - Sophisticated forms of nanotechnology will find some of their first real-world applications in biomedical research, disease diagnosis and, possibly, therapy
    Alivisatos, AP
    [J]. SCIENTIFIC AMERICAN, 2001, 285 (03) : 66 - 73
  • [2] Structure and bonding of gold metal clusters, colloids, and nanowires studied by EXAFS, XANES, and WAXS
    Benfield, RE
    Grandjean, D
    Kröll, M
    Pugin, R
    Sawitowski, T
    Schmid, G
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2001, 105 (10) : 1961 - 1970
  • [3] Spin-dependent tunneling in self-assembled cobalt-nanocrystal superlattices
    Black, CT
    Murray, CB
    Sandstrom, RL
    Sun, SH
    [J]. SCIENCE, 2000, 290 (5494) : 1131 - 1134
  • [4] Infrared and EXAFS study of compositional effects in nanoscale colloidal palladium-copper alloys
    Bradley, JS
    Via, GH
    Bonneviot, L
    Hill, EW
    [J]. CHEMISTRY OF MATERIALS, 1996, 8 (08) : 1895 - 1903
  • [5] Semiconductor nanocrystals as fluorescent biological labels
    Bruchez, M
    Moronne, M
    Gin, P
    Weiss, S
    Alivisatos, AP
    [J]. SCIENCE, 1998, 281 (5385) : 2013 - 2016
  • [6] Using biofunctional magnetic nanoparticles to capture vancomycin-resistant enterococci and other gram-positive bacteria at ultralow concentration
    Gu, HW
    Ho, PL
    Tsang, KWT
    Wang, L
    Xu, B
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2003, 125 (51) : 15702 - 15703
  • [7] STRUCTURE OF POLYMER-PROTECTED PALLADIUM PLATINUM BIMETALLIC CLUSTERS AT THE OXIDIZED STATE - EXTENDED X-RAY ABSORPTION FINE-STRUCTURE ANALYSIS
    HARADA, M
    ASAKURA, K
    UEKI, Y
    TOSHIMA, N
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1992, 96 (24) : 9730 - 9738
  • [8] STRUCTURAL-ANALYSIS OF POLYMER-PROTECTED PALLADIUM RHODIUM BIMETALLIC CLUSTERS USING EXAFS SPECTROSCOPY
    HARADA, M
    ASAKURA, K
    UEKI, Y
    TOSHIMA, N
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1993, 97 (41) : 10742 - 10749
  • [9] MAGNETOOPTICAL KERR SPECTROSCOPY OF A NEW CHEMICALLY ORDERED ALLOY - CO3PT
    HARP, GR
    WELLER, D
    RABEDEAU, TA
    FARROW, RFC
    TONEY, MF
    [J]. PHYSICAL REVIEW LETTERS, 1993, 71 (15) : 2493 - 2496
  • [10] HILL EK, 1996, J PHYS CHEM-US, V100, P3102