In:
MRS Proceedings, Springer Science and Business Media LLC, Vol. 704 ( 2001)
Abstract:
SiO 2 nanospheres have been produced via a high temperature evaporation process and they have been Ni or Ag plated using electroless plating solutions. These samples were examined by Atomic Force Microscopy (AFM) and Magnetic Resonance (MR). The initial SiO 2 nanospheres were about 30 nm in diameter, and the Ni plating layer resulted in a 25nm thick metallic Ni coverage, while the Ag coverage was estimated to be in the 150 nm range. In the case of the Ni/SiO 2 nanosphere composites, the MR signals show the presence of Ni +2 and Ni +3 paramagnetic centers, seen below 40K, and ferromagnetic metallic Ni, which is seen above 40K. The dried Ni plating solution (with no SiO 2 ) shows only the presence of paramagnetic Ni +3 . These results suggest that an interfacial reaction at the surface of the SiO 2 nanospheres leads to the formation of ferromagnetic Ni, which deposits onto the spheres and forms a ferromagnetic Ni/SiO 2 nanosphere composite. In the case of the Ag/SiO 2 nanosphere composites, no MR signal is seen from the non-magnetic Ag, but strong paramagnetic behavior has been noted for Co +2 , which originates from the plating solution.
Type of Medium:
Online Resource
ISSN:
0272-9172
,
1946-4274
DOI:
10.1557/PROC-704-W10.5.1
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2001
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