Abstract:
Interest in mixed-valent perovskite manganese oxides of La\-xAxMnO^ (v4-divalent alkaline
earth Ca, Sr or Ba), whose unusual properties were discovered nearly a half century
ago, has recently been revived. The discovery of the colossal magnetoresistance and pressure
effects introduced new questions concerning the complex interplay between lattice
structure, magnetism and transport in doped perovskite manganites. In this study, we
report our experimental investigations of pressure and magnetic field dependencies of
La-i/sCai/sMnOs (LCMO) epitaxial films with various thickness on SrTiO$ substrate.
An analysis of film thickness dependency of the resistivity of LCMO epitaxial films under
pressure and magnetic field has been performed by taking into account substrate
contributions. This verifies the correlation of lattice distortion with magnetic and transport
properties. Strong dependencies of Mn — O — Mn bond bending and Mn — O bond
stretching with pressure as well as Mn spin alignment with magnetic field, and the lattice
distortion induced by the substrate are discussed.
