Interactions of polarons in poly(3-dodecythiophene) at low temperature

• Published in: Synthetic metals Vol. 159; no. 7; pp. 613 - 618
• Main Authors: CIK, G, DLHAN, L, SERSEN, F, PLECENIK, T, CERVEN, I
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2009; Elsevier
• Subjects: Applied sciences; Conducting polymers; Electrical, magnetic and optical properties; Exact sciences and technology; Magnetism; Organic polymers; Physicochemistry of polymers; Polarons; Poly(3-dodecylthiophene); Polyalkylthiophenes; Properties and characterization; Conducting polymers; Polyalkylthiophenes; Magnetism; Poly(3-dodecylthiophene); Polarons; Polaron; Magnetic relaxation; Aromatic polymer; Iron III Chlorides; Experimental study; Thin film; Magnetization curve; Thiophene derivative polymer; Morphology; Doped polymer; Magnetic properties; Low temperature
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2008.12.005

Zero-field cooled-field-cooled (ZFC-FC) technique was used to investigate the effect of low temperature (4.6 K) on the interactions of polarons in weakly FeCl 3-doped poly(3-dodecylthiophene (PDDT). It was found that the magnetic properties of the system changed with the length of time system spent at low temperature: the Currie–Weiss paramagnetism gradually changed over to “antiferromagnetism” and ultimately to diamagnetism. This effect is connected with the thermochromic properties of self-organized PDDT in primary (10–15 nm) or secondary (30–50 nm) induced aggregates, in which cooling under the glass transition temperature T g (∼240 K) causes extension of the effective conjugation length of coplanar polymer chains. Changes in magnetic properties are related to the inter- and intra-chain interactions of polaron states within both the primary and secondary induced aggregates.