https://doi.org/10.1007/s100510170157
Low temperature magneto-conductivity properties of micro-sized Ag/HD-PE metal/polymers
1
INFM - Università di Napoli Federico II, Dip. Scienze Fisiche, P.le Tecchio n. 80, 80125, Napoli, Italy
2
Università di Napoli Federico II, Dip. di Ing. dei Materiali e della Produzione, P.le Tecchio n. 80, 80125, Napoli, Italy
Corresponding author: a gpepe@na.infn.it
Received:
17
October
2000
Revised:
22
February
2001
Published online: 15 June 2001
A composite material of a polyethylene matrix filled by a fine silver powder
was prepared with different Ag contents and physical behaviours ranging from
insulator to conductor. Ac differential magnetic susceptibility χ measurements
show the samples are paramagnetic up to an Ag concentration of ~65% . At low
temperatures the composite is spin-glass type, whereas the transition from
insulator to conductor corresponds to an abatement of χ at zero magnetizing
field. Magneto-conductivity effects have been observed in resistivity
measurements at low temperatures. They can be explained in terms of an
effective exchange electronic scattering mechanism between the conduction
electrons and the diluted magnetic moments arising from unpaired electron
spins of boundary silver particles. Moreover, the presence of a broad minimum
in the resistivity curve at K, observed in samples with an Ag
concentration just above the percolation threshold, addresses to possible
interference effects similar to those reported in disordered materials.
PACS: 72.80.-r – Conductivity of specific materials / 72.80.Le – Polymers; organic compounds (including organic semiconductors) / 81.05.Lg – Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001