2008/04/26 by O. F. de Lima, J. A. H. Coaquira, R. L. de Almeida +2
Materials Science · Physics and Astronomy · #Chemical and Physical Properties of Materials #Magnetic and transport properties of perovskites and related materials #Multiferroics and related materials #cond-mat.str-el
paper · pdf · doi:10.1063/1.3054323
27 pages, 9 figures
arxiv created 2008/04/26 · openalex publication_date 2009/01/01 · arxiv updated 2009/12/01 · openalex created_date 2019/06/14 · openalex updated_date 2026/08/01
We have investigated the crystal structure and magnetic properties for polycrystalline samples of LaMn1−xFexO3+y, in the whole range 0.0≤x≤1.0, prepared by solid state reaction in air. All samples show the ORT-2 orthorhombic structure that suppresses the Jahn–Teller distortion, thus favoring a ferromagnetic (FM) superexchange interaction between Mn3+–O–Mn3+. For x=0.0 the oxygen excess (y≈0.09) produces vacancies in the La and Mn sites and generates a fraction around 18% of Mn4+ ions and 82% of the usual Mn3+ ions, with possible double-exchange interaction between them. The Fe doping in this system is known to produce only stable Fe3+ ions. We find an evolution from a fairly strong FM phase with a Curie temperature TC∼160 K, for x=0.0, to an antiferromagnetic (AFM) phase with TN=790 K, for x=1.0, accompanied by clear signatures of a cluster-glass behavior. For intermediate Fe contents a mixed-phase state occurs, with a gradual decrease (increase) in the FM (AFM) phase, accompanied by a systematic transition broadening for 0.2<x<0.7. A model based on the expected exchange interaction among the various magnetic-ion types accounts very well for the saturation magnetization (MS) dependence on Fe doping.