Journal of Sol-Gel Science and Technology

, Volume 13, Issue 1–3, pp 503–508 | Cite as

CW and Pulsed EPR Study of Silver Nanoparticles in a SiO2 Matrix

  • G. Mitrikas
  • Y. Deligiannakis
  • C.C. Trapalis
  • N. Boukos
  • G. Kordas


Metallic silver nanoparticles were prepared by the sol-gel method in an SiO2 matrix. The process includes complexation of silicon alkoxides with metal salts, hydrolysis, polycondensation, formation of powder, and subsequent thermal treatment first in oxidizing and second in reducing atmospheres. The sizes of metallic particles were determined both by X-ray diffraction and transmission electron microscopy. These measurements revealed sizes of metallic particles between 1 and 20 nm, depending upon processing conditions. The magnetic properties were investigated using electron paramagnetic resonance spectroscopy in the temperature range between 4 and 300 K. The spin-lattice relaxation time T1 was measured by pulsed EPR. The temperature dependence of T1 is described by the relation 1/T1 ∝ Tn, where 0.4 < n < 1. This behavior is unusual and different from any well-known relaxation processes such as Raman, Direct or the Orbach-Aminov.

silver nanoparticles spin-lattice relaxation pulsed EPR 


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Copyright information

© Kluwer Academic Publishers 1998

Authors and Affiliations

  • G. Mitrikas
    • 1
  • Y. Deligiannakis
    • 1
  • C.C. Trapalis
    • 1
  • N. Boukos
    • 1
  • G. Kordas
    • 1
  1. 1.Institute of Material ScienceNCSR Demokritos 15310Aghia Paraskevi, AthensGreece

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