Abstract
We have studied defect-rich vanadium oxide nanotubes, with reduced V 4+ concentration, by means of x-ray diffraction, infrared spectroscopy, x-ray photoemission spectroscopy, and electron spin resonance (ESR) measurements. In particular, prominent anomalies at 320 and 370 K attributed to structural phase transitions were manifest in the ESR measurements. The ESR spin susceptibility exhibited a singlet-triplet transition of the spin dimers and an antiferromagnetic exchange coupling. In the high-temperature region above 370 K, where the two distinct ESR lines merged, an activation energy of the fast hopping polaron motion, 0.48 eV, was obtained.
Original language | English |
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Article number | 044313 |
Journal | Journal of Applied Physics |
Volume | 106 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2009 |
Bibliographical note
Funding Information:This work was supported by the Korea Ministry of Education, Science and Technology (NRL Program Contract No. R0A-2008-000-20066-0, User Program of Proton Engineering Frontier Project, Contract No. 20090082672), and by the Seoul Research and Business Development Program (Grant No. 10583). The measurements at the Korean Basic Science Institute (KBSI) are acknowledged.
ASJC Scopus subject areas
- General Physics and Astronomy