title: Doping effects in single-layered La0.5Sr1.5MnO4 manganite.
abstract: In this paper we report the results of the synthesis and structural, transport, and magnetic characterization of pure La(0.5)Sr(1.5)MnO(4) and B-site lightly doped samples, i.e. La(0.5)Sr(1.5)Mn(0.95)B(0.05)O(4), where B = Ru, Co, and Ni. The choice was made in order to probe the charge ordering/orbital ordering ground state of the monolayered La(0.5)Sr(1.5)MnO(4) manganite as a consequence of the cation doping. It is shown that even a light doping is successful in suppressing the charge and orbital order found in pure La(0.5)Sr(1.5)MnO(4). No long-range magnetic order has been detected in any of the doped samples but the setup of a spin-glass state with a common freezing temperature ( approximately 22 K). Structural parameters show an anisotropy in the lattice constant variation, with the tetragonal distortion increasing as the cell volume reduces, which may suggest a variation in the orbital character of the e(g) electrons along with the overall cation size.
authors.affiliation: Dipartimento di Chimica Fisica M. Rolla, INSTM, Università di Pavia, Via le Taramelli 16, I-27100, Pavia, Italy. lorenzo.malavasi@unipv.it
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Malavasi
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Mozzati
authors.forename: Clemens
authors.initials: C
authors.lastname: Ritter
authors.forename: Vladimir
authors.initials: V
authors.lastname: Pomjakushin
authors.forename: Cristina
authors.initials: C
authors.lastname: Tealdi
authors.forename: Carlo Bruno
authors.initials: CB
authors.lastname: Azzoni
authors.forename: Giorgio
authors.initials: G
authors.lastname: Flor