Intermediate-valence icosahedral Au-Al-Yb quasicrystal
Intermediate-valence icosahedral Au-Al-Yb quasicrystal
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DOI：
10.1103/physrevb.86.094201
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发表时间：
2012-09
影响因子：
3.7
通讯作者：
T. Watanuki;S. Kashimoto;D. Kawana;Teruo Yamazaki;A. Machida;Yukinori Tanaka;Taku J. Sato
中科院分区：
文献类型：
--
作者：
T. Watanuki;S. Kashimoto;D. Kawana;Teruo Yamazaki;A. Machida;Yukinori Tanaka;Taku J. Sato
A quasiperiodic intermediate-valence (IV) system is realized in an icosahedral Au-Al-Yb quasicrystal. X-ray absorption spectroscopy near the Yb ${L}_{3}$ edge indicates that quasiperiodically arranged Yb ions assume a mean valence of 2.61, between a divalent state ($4{f}^{14}$, $J=0$) and a trivalent one ($4{f}^{13}$, $J=7/2$). Magnetization measurements demonstrate that the $4f$ holes in this quasicrystal have a localized character. The magnetic susceptibility shows a Curie-Weiss behavior above $\ensuremath{\sim}100$ K with an effective magnetic moment of 3.81${\ensuremath{\mu}}_{\mathrm{B}}$ per Yb. Moreover, a crystalline approximant to this quasicrystal is an IV compound. We propose a heterogeneous IV model for the quasicrystal, whereas the crystalline approximant is most likely a homogeneous IV system. At temperatures below $\ensuremath{\sim}10$ K, specific heat and magnetization measurements reveal non-Fermi-liquid behavior in both the quasicrystal and its crystalline approximant without either doping, pressure, or field tuning.
A quasiperiodic intermediate-valence (IV) system is realized in an icosahedral Au-Al-Yb quasicrystal. X-ray absorption spectroscopy near the Yb ${L}_{3}$ edge indicates that quasiperiodically arranged Yb ions assume a mean valence of 2.61, between a divalent state ($4{f}^{14}$, $J=0$) and a trivalent one ($4{f}^{13}$, $J=7/2$). Magnetization measurements demonstrate that the $4f$ holes in this quasicrystal have a localized character. The magnetic susceptibility shows a Curie-Weiss behavior above $\ensuremath{\sim}100$ K with an effective magnetic moment of 3.81${\ensuremath{\mu}}_{\mathrm{B}}$ per Yb. Moreover, a crystalline approximant to this quasicrystal is an IV compound. We propose a heterogeneous IV model for the quasicrystal, whereas the crystalline approximant is most likely a homogeneous IV system. At temperatures below $\ensuremath{\sim}10$ K, specific heat and magnetization measurements reveal non-Fermi-liquid behavior in both the quasicrystal and its crystalline approximant without either doping, pressure, or field tuning.