Low-temperature magnetoresistance of layered cobalt oxides Nax CoO2

Hirotaka Okabe, Jun Akimitsu, Takashi Kubodera, Masanori Matoba, Toru Kyomen, Mitsuru Itoh

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

We measured transport properties in layered cobalt oxides Nax CoO2, that are parent materials of the superconductor Nax CoO2 · y H2 O, in order to reveal so-far unsettled origin of these electronic and magnetic features. Various sodium nonstoichiometric samples Nax CoO2 ( x = 0.47, 0.62, 1.0) have been carefully synthesized to control the carrier density and the electronic state of cobalt ions. We found a large negative magnetoresistance (MR) effect in the vicinity of x ∼ 0.5 and 1.0. The x = 0.47 and 1.0 samples show negative MR, - 45 % and - 10 %, respectively, at 90 kOe and 4 K. These negative MR suggest the pseudogap formation due to the charge ordering in CoO2 layers, such as Ca3 Co4 O9 and Bi2 - x Pbx Sr2 Co2 Oy, all of which exhibit similar behaviors. The suppression of the pseudogap by a magnetic field causes the large negative magnetoresistance.

Original languageEnglish
Pages (from-to)863-864
Number of pages2
JournalPhysica B: Condensed Matter
Volume378-380
Issue numberSPEC. ISS.
DOIs
Publication statusPublished - May 1 2006
Externally publishedYes

Keywords

  • Cobalt oxide
  • Magnetoresistance
  • Transport property

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Low-temperature magnetoresistance of layered cobalt oxides Na<sub>x</sub> CoO<sub>2</sub>'. Together they form a unique fingerprint.

  • Cite this

    Okabe, H., Akimitsu, J., Kubodera, T., Matoba, M., Kyomen, T., & Itoh, M. (2006). Low-temperature magnetoresistance of layered cobalt oxides Nax CoO2. Physica B: Condensed Matter, 378-380(SPEC. ISS.), 863-864. https://doi.org/10.1016/j.physb.2006.01.319