Structural, magnetic, transport, and thermoelectric properties of the pseudobrookite AlTi2 O5-Ti3 O5 system

Ryusei Takahama, Toi Ishii, Daigo Indo, Mitsutoshi Arizono, Chieko Terakura, Yoshinori Tokura, Nao Takeshita, Masaaki Noda, Hideki Kuwahara, Takuo Saiki, Takuro Katsufuji, Ryoichi Kajimoto, Tetsuji Okuda*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

We investigated the structural, magnetic, transport, and high-temperature thermoelectric properties of single crystals of the pseudobrookite Al1-xTi2+xO5 for 0≤x≤1 grown using a floating zone. We found a correlation of spin-singlet Ti3+-Ti3+ dimers coupled with the lattice even in the conductive α and λ phases which develops with increasing x. This developing dimer correlation reduces the number of unpaired Ti3+ ions, which makes the compound more conductive owing to the suppression of disorder for x up to about 0.75. The dimer fluctuation causes a critical enhancement of the magnetic susceptibility at around 150 K in the λ phase near the boundary (x∼0.9) between the λ and the β phases. Such a correlation of the spin-singlet Ti3+-Ti3+ dimers may produce a high Seebeck coefficient in the conductive α and λ phases leading to a large thermoelectric power factor at high temperatures.

Original languageEnglish
Article number074401
JournalPhysical Review Materials
Volume4
Issue number7
DOIs
Publication statusPublished - 2020 Jul

ASJC Scopus subject areas

  • Materials Science(all)
  • Physics and Astronomy (miscellaneous)

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