title: Chemical size effect on the magnetic and electrical properties in the (Tb(1-)(x)Eu(x))MnO(3) (0 < or = x < or = 1.0) system.
abstract: The effect of isovalent chemical substitution of Eu3+ into the Tb3+ sites on the magnetic and electrical properties of (Tb1-xEux)MnO3 (0 </= x </= 1.0) system has been investigated. The orthorhombic structure with space group Pbnm is observed in this series of materials. An increase in Mn-O bond distance with increasing Eu content leads to improvement in the overlap between the Mn 3d and O 2p orbital thereby causing a decrease in activation energy and resistivity. Moreover, as the Eu content increases, the effective moments (mueff) are reduced linearly and an exchange coupling is observed in Tb-Tb, Tb-Eu, and Eu-Eu complexes for x = 0.1 and 0.3 samples. Both these features can be related to the substitution of bigger Eu3+ ions replacing the original Tb-Tb coupling.
authors.affiliation: Department of Chemistry and Center for Nano Storage Research, National Taiwan University, Taipei 106, Taiwan.
authors.forename: T S
authors.initials: TS
authors.lastname: Chan
authors.forename: R S
authors.initials: RS
authors.lastname: Liu
authors.forename: C C
authors.initials: CC
authors.lastname: Yang
authors.forename: W-H
authors.initials: WH
authors.lastname: Li
authors.forename: Y H
authors.initials: YH
authors.lastname: Lien
authors.forename: C Y
authors.initials: CY
authors.lastname: Huang
authors.forename: J-F
authors.initials: JF
authors.lastname: Lee