Role of Oxygen Electrons in the Metal-Insulator Transition in the Magnetoresistive Oxide La2-2xSr1+2xMn2O7 Probed by Compton Scattering

被引：27

作者：

Barbiellini, B. ^{[1
]}

Koizumi, A. ^{[2
]}

Mijnarends, P. E. ^{[1
,3
]}

Al-Sawai, W. ^{[1
]}

Lin, Hsin ^{[1
]}

Nagao, T. ^{[2
]}

Hirota, K. ^{[4
]}

Itou, M. ^{[5
]}

Sakurai, Y. ^{[5
]}

Bansil, A. ^{[1
]}

机构：

[1] Northeastern Univ, Dept Phys, Boston, MA 02115 USA

[2] Univ Hyogo, Grad Sch Mat Sci, Kamigori Cho, Hyogo 6781297, Japan

[3] Delft Univ Technol, Fac Sci Appl, Dept Radiat Radionuclides & Reactors, Delft, Netherlands

[4] Osaka Univ, Grad Sch Sci, Dept Earth & Space Sci, Osaka 5600043, Japan

[5] Japan Synchrotron Radiat Res Inst, SPring 8, Sayo, Hyogo 6795198, Japan

来源：

PHYSICAL REVIEW LETTERS | 2009年 / 102卷 / 20期

关键词：

CONDENSED-MATTER PHYSICS; X-RAY SPECTROMETER; MANGANITE LA2-2XSR1+2XMN2O7; DIFFRACTION; LASR2MN2O7;

D O I：

10.1103/PhysRevLett.102.206402

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

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.

引用

页数：4