Onset of metallic ferromagnetism in a doped spin–orbital chain

Abstract Starting from a spin–orbital model for doped manganites, we investigate a competition between ferromagnetic and antiferromagnetic order in a one‐dimensional model at finite temperature. The magnetic and orbital order at half filling support each other and depend on a small antiferromagnetic superexchange between t 2 g spins and on an alternating Jahn–Teller potential. The crossover to a metallic ferromagnetic phase found at finite doping is partly suppressed by the Jahn–Teller potential which may localize e g electrons. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)