Abstract :
The electrical and magnetic properties of Pr3±-doped Ruddlesden–Popper manganates with the formula, CaO(Pr0.08Ca0.92MnO3)n (n=1,2,3 and ∞) 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.
