Investigation of the electrical and magnetic properties of electron-doped Ruddlesden-Popper phases, CaO(Pr0.08Ca0.92MnO3)n (n=1, 2, 3 and ∞)

The electrical and magnetic properties of Pr3+/--doped Ruddlesden-Popper manganates with the formula, CaO(Pr0.08Ca0.92 MnO3)(n) (n = 1,2,3 and infinity) have been investigated. The electrical conductivity of the samples increases with the number of perovksite slabs sandwiched between the rock-salt-like CaO layers. Magnetic susceptibility measurements show an anomalous behavior for the n = 1 composition which is attributed to the near absence of ferromagnetic correlations in a two-dimensional system. The magnetic behavior of other members can, however, be understood on the basis of a 'ferromagnetic-droplet' model. Since the number of electrons per perovskite slab is invariant across the series, the electronic properties are readily correlated to the phase space available for exchange interactions. (C) 2003 Elsevier Science Ltd. All rights reserved.