title: Field-induced ferromagnetic metallic state of bilayer manganite (La0.4Pr0.6)1.2Sr1.8Mn2O7: a polarized neutron diffraction study.
abstract: Unpolarized and polarized neutron diffraction measurements have been carried out on the bilayer manganite (La0.4Pr0.6)1.2Sr1.8Mn2O7 which undergoes simultaneous semiconductor-metal paraferromagnetic transitions under magnetic field. Maximum entropy magnetization density reconstruction and multipole refinement on flipping ratios evidence the existence of two distinct field-induced states. The field-induced ferromagnetic state where the field is parallel to the c axis is characterized by the presence of magnetic moment on the Sr site of 0.48(2)mu(B), due to the Pr substitution. It also shows a high population of the d3(z(2)-r(2)) orbitals of Mn3+. For the field-induced state where the field is parallel to the a or b axes no magnetization density was found at the Sr site and the dx(2)(-y(2)) orbital is slightly more populated than the d3(z(2)-r(2)) one.
authors.affiliation: Laboratoire Léon Brillouin (CEA-CNRS), CE Saclay, 91191 Gif sur Yvette, France.
authors.forename: F
authors.initials: F
authors.lastname: Wang
authors.forename: A
authors.initials: A
authors.lastname: Gukasov
authors.forename: F
authors.initials: F
authors.lastname: Moussa
authors.forename: M
authors.initials: M
authors.lastname: Hennion
authors.forename: M
authors.initials: M
authors.lastname: Apostu
authors.forename: R
authors.initials: R
authors.lastname: Suryanarayanan
authors.forename: A
authors.initials: A
authors.lastname: Revcolevschi