Publication Date:
2015-03-25
Description:
We report on the calorimetric and magnetic properties of the polyaniline hydrochloride in order to discuss its metallicity. Both the specific heat and the magnetic susceptibility χ have been investigated as a function of temperature from 300 K down to 2 K. The measurements of the specific heat have allowed us to determine the electronic Sommerfeld coefficient γ and the temperature dependence of the susceptibility has revealed a Pauli-like component. By combining χ and γ , the dimensionless Wilson ratio R W ∝ χ / γ demonstrates that the universal free electrons limit is reached above 100 K as a strong check of the metallicity of this conducting polymer. By removing the Pauli component from the measured susceptibility, the resulting contribution displays below 100 K a well-defined Curie-like component in agreement with a few percents of spins localized by disorder at low temperatures. These results are therefore consistent with an electronic itinerancy, namely, a metallic state even in the presence of disorder.
Print ISSN:
0021-8979
Electronic ISSN:
1089-7550
Topics:
Physics
