Combined metamagnetic and insulator-to-metal transitions in Pr-based manganites

A new mechanism of the simultaneous metamagnetic and insulator-to-metal tra nsition caused by an external magnetic Field is proposed. It makes it possi ble to explain specific properties of Pr-based doped manganites by the exis tence of Pr4+ ions in them at zero magnetic field. In finite fields. transf er of holes to the Mn ions takes place which manifests itself as a such a c ombined transition. On increase in temperature, a transition to a highly-co nductive state can take place in the absence of the magnetic field. (C) 200 0 Elsevier Science B.V. All rights reserved.