ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Samples of trans-polyacetylene, (CH)x, were doped with the magnetic ion, FeCl−4, by immersion in nitromethane solutions of FeCl3. The resulting dopant levels ranged over two orders of magnitude. ESR spectra and spin–lattice relaxation times, T1, were measured for the undoped polymer and lightly doped polymer over the temperature range 1.5–120 K. The ESR spectra of trans-(CH)x lightly doped (〈1 mol % Fe−4 ) with FeCl−4 exhibit a narrow (ΔH≈5–10 G at 4.2 K) g=2.003 signal which decreases in relative amplitude with increasing dopant level, and broad signals at g=2 (ΔH≈500 G), which increases with increasing dopant level, and at g=4.3 (ΔH≈200 G). The narrow signal is the intrinsic trans-(CH)x signal; the broad signals are attributable to iron. T1 for the narrow signal is approximately one-half of the value of undoped trans-(CH)x at 4.2 K. dc susceptibilities for all of the doped samples were measured over the temperature range of 1.5–300 K. The magnetically doped samples all exhibit Curie law behavior, and an analysis of the magnetization data yields an effective moment, Jeff, equal to 2.77, close to the value 5/2 expected for Fe(III).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.453928
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