title: Mn3+ in trigonal bipyramidal coordination: a new blue chromophore.
abstract: We show that trivalent manganese, Mn(3+), imparts an intense blue color to oxides when it is introduced at dilution in trigonal bipyramidal coordination. Our optical measurements and first-principles density functional theory calculations indicate that the blue color results from an intense absorption in the red/green region. This absorption is due in turn to a symmetry-allowed optical transition between the valence-band maximum, composed of Mn 3d(x(2)-y(2),xy) states strongly hybridized with O 2p(x,y) states, and the narrow Mn 3d(z(2))-based conduction-band minimum. We begin by demonstrating and explaining the effect using a well-defined prototype system: the hexagonal YMnO(3)-YInO(3) solid solution. We then show that the behavior is a general feature of diluted Mn(3+) in this coordination environment.
authors.affiliation: Department of Chemistry, Oregon State University, Corvallis, Oregon 97330-4003, USA.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Smith
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mizoguchi
authors.forename: Kris
authors.initials: K
authors.lastname: Delaney
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Spaldin
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Sleight
authors.forename: M A
authors.initials: MA
authors.lastname: Subramanian