Local electronic state in the high-valence hollandite chromium oxide K_2Cr_8O_<16> investigated by ^<53>Cr NMR
Local electronic state in the high-valence hollandite chromium oxide K_2Cr_8O_<16> investigated by ^<53>Cr NMR
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^<53>Cr NMR研究高价锰铝石氧化铬K_2Cr_8O_<16>中的局域电子态
DOI：
10.1103/physrevb.88.165107
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发表时间：
2013
影响因子：
3.7
通讯作者：
Hikaru Takeda
中科院分区：
文献类型：
--
作者：
Y. Shimizu;S. Aoyama;T. Jinno;M. Itoh;Y. Ueda;糀谷浩，井上徹，赤荻正樹;渡邉昇;Hikaru Takeda
我们进行了Cr NMR测量来研究在95 K铁磁相中经历了不寻常的金属-绝缘体（MI）转变的一种Hollandite型氧化铬KCrO的局域电子态。在铁磁绝缘相，我们观察到的NMR谱与内部领域彼此不同的四个Cr网站。通过对超精细场的分析，发现各向同性内场的差异与超转移超精细（STH）场有关。通过不同的STH场，检测到在四个Cr位的3轨道的电子占据的微小差异，所述STH场由不同的电荷转移通道控制。STH场的存在显示了铬3轨道和氧2轨道的强杂化，这导致了特征的MI跃迁。
We have performedCr NMR measurements to investigate the local electronic state of a hollandite-type chromium oxide KCrOwhich undergoes an unusual metal-insulator (MI) transition at95 K in the ferromagnetic phase. In the ferromagnetic insulating phase, we observed NMR spectra with internal fields different from each other at the four Cr sites. From an analysis of the hyperfine fields, the difference in the isotropic internal field is related to the supertransferred hyperfine (STH) field. The slight difference in the electron occupation of the 3orbital at the four Cr sites is detected through the different STH field governed by the different charge-transfer passes. The presence of the STH field shows the strong hybridization of the chromium 3orbitals and oxygen 2orbital which leads to the characteristic MI transition.