A theory of colossal-magnetoresistance Pr-based manganites

Specific properties of Pr-based doped manganites are related to the existen ce of Pr4+ ions in them at zero magnetic field. In finite fields, transfer of holes to the Mn ions takes place which manifests itself as a joint metam agnetic and insulator-to-metal transition. On increase in temperature, a tr ansition to a highly conductive state can take place in the absence of the magnetic field. (C) 2000 Elsevier Science B.V. All rights reserved.