title: Temperature-dependent orbital degree of freedom of a bilayer manganite by magnetic compton scattering.
abstract: We have measured temperature-dependent magnetic Compton profiles (MCPs) from a single crystal of La1.2Sr1.8Mn2O7. The MCPs, which involved the scattering of circularly polarized x rays, are in general related to the momentum density of all the unpaired spins in the system. Nevertheless, we show that when the x-ray scattering vector lies along the [110] direction, the number of magnetic electrons of a specific symmetry, i.e., d electrons of x(2)-y(2) symmetry, yield a distinct signature in the MCP, allowing us to monitor substantial changes in the occupancy of the dx(2)(-y(2)) states over the investigated temperature range of 5-200 K. This study indicates that magnetic Compton scattering can provide a powerful window on the properties of specific magnetic electrons in complex materials.
authors.affiliation: Department of Physics, University of Illinois, Chicago, Illinois 60680, USA.
authors.forename: Yinwan
authors.initials: Y
authors.lastname: Li
authors.forename: P A
authors.initials: PA
authors.lastname: Montano
authors.forename: J F
authors.initials: JF
authors.lastname: Mitchell
authors.forename: B
authors.initials: B
authors.lastname: Barbiellini
authors.forename: P E
authors.initials: PE
authors.lastname: Mijnarends
authors.forename: S
authors.initials: S
authors.lastname: Kaprzyk
authors.forename: A
authors.initials: A
authors.lastname: Bansil