title: Persistence of magnons in a site-diluted dimerized frustrated antiferromagnet.
abstract: We present inelastic neutron scattering and thermodynamic measurements characterizing the magnetic excitations in a disordered spin-liquid antiferromagnet with non-magnetic substitution. The parent compound Ba(3)Mn(2)O(8) is a dimerized, quasi-two-dimensional geometrically frustrated quantum disordered antiferromagnet. We substitute this compound with non-magnetic V(5+) for the S=1 Mn(5+) ions, Ba(3)(Mn(1-x)V (x))(2)O(8), and find that the singlet-triplet excitations which dominate the spectrum of the parent compound persist for the full range of substitution examined, up to x=0.3. We also observe additional low-energy magnetic fluctuations which are enhanced at the greatest substitution values.
authors.affiliation: Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA. stonemb@ornl.gov
authors.forename: M B
authors.initials: MB
authors.lastname: Stone
authors.forename: A
authors.initials: A
authors.lastname: Podlesnyak
authors.forename: G
authors.initials: G
authors.lastname: Ehlers
authors.forename: A
authors.initials: A
authors.lastname: Huq
authors.forename: E C
authors.initials: EC
authors.lastname: Samulon
authors.forename: M C
authors.initials: MC
authors.lastname: Shapiro
authors.forename: I R
authors.initials: IR
authors.lastname: Fisher