Abstract

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.

Notes

Originally published in Physical Review Letters v.102 (2009): 206402. DOI: a href="http://link.aps.org/doi/10.1103/PhysRevLett.102.206402"> 10.1103/PhysRevLett.102.206402

Keywords

oxygen electrons, bilayer manganite, Compton scattering, Curie temperature, La2-2xSr1+2xMn2O7

Subject Categories

Anisotropy, Electrons - Scattering

Disciplines

Physics

Publisher

American Physical Society

Publication Date

5-20-2009

Rights Information

Copyright 2009 American Physical Society.

Rights Holder

American Physical Society

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