Progress of Cryogenics and Isotopes Separation , ISSN: 1582-2575
2010, Volume 13, Issue 2

Influence of Mn Substitution with Fe/Co on Magnetic Structure and Transport Mechanisms in Some Manganites

Abstract

Many manganites are known as ferromagnetic materials, with a “bad metal” behavior, and a transition temperature close to Curie temperature. The manganites with La_0.54Ho_0.11Sr_0.35Mn_1-x(Co/Fe)_xO₃ were prepared by means of sol-gel methods. The treated samples were monitorized by XRD, while magnetic properties of the samples were investigate with a Foner type magnetometer, between 77 and 400 K, using a magnetic field H=1.4 T. Magnetoresistance data were obtained with a four probe method, in a magnetic field H_max = 1 T, between 7 and 350 K. Treated samples contain only perovskite type phases, depending on the Mn substitution. Structure modification, magnetic properties and transport mechanisms are discussed, in agreement with the Sr/Ca doping.