Electronic structure of manganese in GMR perovskites as seen by the soft X-ray absorption spectroscopy

The changes in the electronic structure of manganese perovskites Ln(1-X)A(X)MnO(3) (Ln = La, Pr; A = Ca, Sr, Ba; 0 less than or equal to x less than or equal to 0.33) exhibiting GMR properties have been investigated above and below the transition temperature by soft X-ray Absorption Spectroscopy at Mn L-2,L-3-edge. The analysis of the Mn L-3-edges both in the paramagnetic-insulating state and in the metallic-ferromagnetic stale have been performed by a linear combination of a Mn(IV) reference and two simulated spectra corresponding to High Spin and Low Spin Mn(III). The results of the simulation, although not perfect, indicate that, upon crossing the transition, a change occurs in the ratio HS/LS of Mn(III) states.