Observation of ferromagnetic ordering in conjugated polymers exhibiting OMAR effect

S. Majumdar, J. O. Lill, J. Rajander, H. Majumdar

Research output: Contribution to journalArticleScientificpeer-review

3 Citations (Scopus)

Abstract

We report observation of ferromagnetic (FM) ordering in π-conjugated polymeric semiconductors, namely regio-regular poly (3-hexyl thiophene) (RRP3HT) and 1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene (PCBM), in the temperature range of 5–300 K. Diodes made from these polymers exhibit sizable magnetoresistance (known commonly as OMAR). However, upon blending these two materials, the FM ordering is suppressed by a huge paramagnetic (PM) signal. In the diodes with RRP3HT:PCBM blend showing PM response, OMAR decreases substantially. Particle induced X-ray emission spectroscopy indicate presence of dilute magnetic impurities as residues from the synthesis process in the individual polymers. However the impurity signal is unable to explain the temperature dependence of magnetization in these materials and the observed paramagnetism of the RRP3HT:PCBM blend. We propose a hypothesis for the origin of the FM nature of these polymers based on ours and previously reported experimental observations and pointed out that the reported organic magnetoresistance might have a close correlation with the ferromagnetic interaction in these polymers.
Original languageEnglish
Pages (from-to)66-72
JournalOrganic electronics
Volume21
DOIs
Publication statusPublished - 2015
MoE publication typeA1 Journal article-refereed

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Conjugated polymers
Thiophenes
Polymers
Magnetoresistance
Diodes
Impurities
Paramagnetism
Magnetization
Semiconductor materials
Temperature

Cite this

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title = "Observation of ferromagnetic ordering in conjugated polymers exhibiting OMAR effect",
abstract = "We report observation of ferromagnetic (FM) ordering in π-conjugated polymeric semiconductors, namely regio-regular poly (3-hexyl thiophene) (RRP3HT) and 1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene (PCBM), in the temperature range of 5–300 K. Diodes made from these polymers exhibit sizable magnetoresistance (known commonly as OMAR). However, upon blending these two materials, the FM ordering is suppressed by a huge paramagnetic (PM) signal. In the diodes with RRP3HT:PCBM blend showing PM response, OMAR decreases substantially. Particle induced X-ray emission spectroscopy indicate presence of dilute magnetic impurities as residues from the synthesis process in the individual polymers. However the impurity signal is unable to explain the temperature dependence of magnetization in these materials and the observed paramagnetism of the RRP3HT:PCBM blend. We propose a hypothesis for the origin of the FM nature of these polymers based on ours and previously reported experimental observations and pointed out that the reported organic magnetoresistance might have a close correlation with the ferromagnetic interaction in these polymers.",
author = "S. Majumdar and Lill, {J. O.} and J. Rajander and H. Majumdar",
year = "2015",
doi = "10.1016/j.orgel.2015.02.025",
language = "English",
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Observation of ferromagnetic ordering in conjugated polymers exhibiting OMAR effect. / Majumdar, S.; Lill, J. O.; Rajander, J.; Majumdar, H.

In: Organic electronics, Vol. 21, 2015, p. 66-72.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Observation of ferromagnetic ordering in conjugated polymers exhibiting OMAR effect

AU - Majumdar, S.

AU - Lill, J. O.

AU - Rajander, J.

AU - Majumdar, H.

PY - 2015

Y1 - 2015

N2 - We report observation of ferromagnetic (FM) ordering in π-conjugated polymeric semiconductors, namely regio-regular poly (3-hexyl thiophene) (RRP3HT) and 1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene (PCBM), in the temperature range of 5–300 K. Diodes made from these polymers exhibit sizable magnetoresistance (known commonly as OMAR). However, upon blending these two materials, the FM ordering is suppressed by a huge paramagnetic (PM) signal. In the diodes with RRP3HT:PCBM blend showing PM response, OMAR decreases substantially. Particle induced X-ray emission spectroscopy indicate presence of dilute magnetic impurities as residues from the synthesis process in the individual polymers. However the impurity signal is unable to explain the temperature dependence of magnetization in these materials and the observed paramagnetism of the RRP3HT:PCBM blend. We propose a hypothesis for the origin of the FM nature of these polymers based on ours and previously reported experimental observations and pointed out that the reported organic magnetoresistance might have a close correlation with the ferromagnetic interaction in these polymers.

AB - We report observation of ferromagnetic (FM) ordering in π-conjugated polymeric semiconductors, namely regio-regular poly (3-hexyl thiophene) (RRP3HT) and 1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene (PCBM), in the temperature range of 5–300 K. Diodes made from these polymers exhibit sizable magnetoresistance (known commonly as OMAR). However, upon blending these two materials, the FM ordering is suppressed by a huge paramagnetic (PM) signal. In the diodes with RRP3HT:PCBM blend showing PM response, OMAR decreases substantially. Particle induced X-ray emission spectroscopy indicate presence of dilute magnetic impurities as residues from the synthesis process in the individual polymers. However the impurity signal is unable to explain the temperature dependence of magnetization in these materials and the observed paramagnetism of the RRP3HT:PCBM blend. We propose a hypothesis for the origin of the FM nature of these polymers based on ours and previously reported experimental observations and pointed out that the reported organic magnetoresistance might have a close correlation with the ferromagnetic interaction in these polymers.

U2 - 10.1016/j.orgel.2015.02.025

DO - 10.1016/j.orgel.2015.02.025

M3 - Article

VL - 21

SP - 66

EP - 72

JO - Organic electronics

JF - Organic electronics

SN - 2109-0688

ER -