Eur. Phys. J. B 22, 157-165 (2001)
https://doi.org/10.1007/s100510170123

Jahn-Teller, charge and magnetic ordering in half-doped manganese oxides

¹ Istituto Nazionale di Fisica della Materia and Dipartimento di Fisica, Università di Roma "La Sapienza" , Piazzale Aldo Moro 2, 00185 Roma, Italy
² Laboratoire d'Études des Propriétés Électroniques des Solides, Centre National de la Recherche Scientifique, associated with Université Joseph Fourier, BP 166, 38042 Grenoble Cedex 9, France

Corresponding author: ^a feinberg@lepes.polycnrs-gre.fr

Received: 28 November 2000
Published online: 15 July 2001

Abstract

The phase diagram of half-doped manganite systems of formula A_0.5A'_0.5MnO₃ is investigated within a single-orbital model incorporating magnetic double-exchange and superexchange, together with intersite Coulomb and electron-lattice interactions. Strong Jahn-Teller and breathing mode deformations compete together and result in shear lattice deformations. The latter stabilize the charge-ordered CE-type phase, which undergo first-order transitions with temperature or magnetic field to either Ferromagnetic metallic or Paramagnetic insulating phases. An essential feature is the self-consistent screening of Coulomb and electron-phonon interactions in the ferromagnetic phase.