Role of Oxygen Electrons in the Metal-Insulator Transition in the Magnetoresistive Oxide La2-2xSr1+2xMn2O7 Probed by Compton Scattering
Role of Oxygen Electrons in the Metal-Insulator Transition in the Magnetoresistive Oxide La2-2xSr1+2xMn2O7 Probed by Compton Scattering
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DOI：
10.1103/physrevlett.102.206402
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发表时间：
2009-05-22
影响因子：
8.6
通讯作者：
Bansil, A.
中科院分区：
文献类型：
--
作者：
Barbiellini, B.;Koizumi, A.;Bansil, A.
本文研究了双层锰氧化物中康普顿剖面的[100]-[110]各向异性。在理论和实验之间发现关于两个金属相中的各向异性的定量一致性（即，低温铁磁相和巨磁阻相。在居里温度以上的顺磁相的动量密度中确定了金属-绝缘体转变的鲁棒签名。我们解释我们的结果提供了直接的证据，从metalliclike的过渡到混合离子-共价键伴随的磁性转变。在这个相变中所涉及的电子的数量估计。我们的研究证明了康普顿散射技术的灵敏度，用于识别参与金属-绝缘体转变的电子的数量和类型。
We have studied the [100]-[110] anisotropy of the Compton profile in the bilayer manganite. Quantitative agreement is found between theory and experiment with respect to the anisotropy in the two metallic phases (i.e., the low temperature ferromagnetic and the colossal magnetoresistant phase under a magnetic field of 7 T). Robust signatures of the metal-insulator transition are identified in the momentum density for the paramagnetic phase above the Curie temperature. We interpret our results as providing direct evidence for the transition from the metalliclike to the admixed ionic-covalent bonding accompanying the magnetic transition. The number of electrons involved in this phase transition is estimated. Our study demonstrates the sensitivity of the Compton scattering technique for identifying the number and type of electrons involved in the metal-insulator transition.