Magnetic phase transition for defect induced electron spins from fully metal-semiconductor separated SWCNTs
- Author(s)
- Marek Havlicek, Alexander Chernov, Wolfgang Jantsch, Zbyslaw Wilamowski, Kazuhiro Yanagi, Hiromichi Kataura, Mark Rümmeli, Hans Malissa, Hans Kuzmany
- Abstract
ESR experiments from PtRhRe grown and highly semiconductor—metal
separated single-walled carbon nanotubes (SWCNTs) were performed at
9.45 GHz and temperatures T between 0.39 and 200 K. No explicit
evidence was found for a response from itinerant electrons in the
metallic tubes. Rather, in both the metallic (M) and the semiconducting
(SC) tubes, the ESR signal originates from quasi-localized defect spins
but interactions with free electrons render the two systems
characteristically different. The spin susceptibility was of Curie–Weiss
type for T ≥ 10 K. For annealed samples it drops for lower T indicating a transition to a ferromagnetic state. Linewidths decrease and increase with increasing T
for M and SC tubes, respectively. As a consequence they cross for the
two systems. Interaction of spins with free carriers in M tubes via an
RKKY type mechanism and increase of linewidth with temperature for SC
tubes due to spin–lattice interaction is suggested to be responsible for
this.
- Organisation(s)
- Electronic Properties of Materials
- External organisation(s)
- Johannes Kepler Universität Linz, Polish Academy of Sciences (PAS), Tokyo Metropolitan University, National Institute of Advanced Industrial Science and Technology (AIST), Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden, Princeton University
- Journal
- Physica Status Solidi. B: Basic Research
- Volume
- 249
- Pages
- 2562-2567
- No. of pages
- 6
- ISSN
- 0370-1972
- DOI
- https://doi.org/10.1002/pssb.201200426
- Publication date
- 2012
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103018 Materials physics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/magnetic-phase-transition-for-defect-induced-electron-spins-from-fully-metalsemiconductor-separated-swcnts(34bf5dbd-a7f4-4b98-b704-c5f6a880496d).html