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arXiv · 1503.02139

Microscopic examinations of Co valences and spin states in electron-doped LaCoO$_{3}$

Keisuke Tomiyasu·Syun-Ichi Koyama·Masanori Watahiki·Mika Sato·Kazuki Nishihara·Yuki Takahashi·Mitsugi Onodera·Kazuaki Iwasa·Tsutomu Nojima·Hiroyuki Nojiri·Jun Okamoto·Di-Jing Huang·Yuuichi Yamasaki·Hironori Nakao·Youichi Murakami
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Abstract

We studied the Co valences and spin states in electron-doped LaCo$_{1-y}$Te$_{y}$O$_3$ by measuring x-ray absorption spectra and electron spin resonance. The low-temperature insulating state involves the low-spin Co$^{3+}$ ($S=0$) and the high-spin Co$^{2+}$ state, which is described by $g=3.8$ and $j_{\rm eff}=1/2$. The results, in concurrence with the electron-hole asymmetry confirmed in electrical resistivity, coincide with a spin-blockade phenomenon in this system. Further, we discuss the $g$ factor in terms of the strong covalent-bonding nature and consider multiple origins of this phenomenon.

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Keisuke Tomiyasu, Syun-Ichi Koyama, Masanori Watahiki, Mika Sato, Kazuki Nishihara, Yuki Takahashi, Mitsugi Onodera, Kazuaki Iwasa, Tsutomu Nojima, Hiroyuki Nojiri, Jun Okamoto, Di-Jing Huang, Yuuichi Yamasaki, Hironori Nakao, Youichi Murakami. 2015-03-07. Microscopic examinations of Co valences and spin states in electron-doped LaCoO$_{3}$. https://doi.org/10.7566/jpsj.85.094702

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