Electrical properties of strontium-substituted ferrimanganites of thulium and itterbium

Background. The essential interrelation of magnetic properties with conducting and ferroelectricproperties of diamagnetic-substituted manganites of rare-earth elements can be used to create various spintronic devices. Most of the experimental studies to date have been devoted to the study of the giant magnetoresistance (GMR) effect in diamagnetically diluted manganites of “light” lanthanides having a perovskite-like crystal lattice. The manganites of the “heavy” lanthanides having a ilmenite-like crystal latticeare less investigated from this point of view. Materials and methods. Manganites of thulium Tm$_{0.65}$Sr$_{0.35}$Fe$_{0.3}$Mn$_{0.7}$O$_{3}$ and ytterbium Yb$_{0.82}$Sr$_{0.18}$Fe$_{0.15}$Mn$_{0.85}$O$_{3}$ with partial replacement of lanthanide to strontium, and manganese to iron are prepared according to ceramic technology. Their electrical conductivity and galvanomagnetic phenomena, including GMR, were studied in a wide range of temperatures and magnetic fields. Results. The temperature dependence of the resistivity, Yb$_{0.82}$Sr$_{0.18}$Fe$_{0.15}$Mn$_{0.85}$O$_{3}$, reveals a metal-insulator transition point (T$_{MI}$), which shifts toward higher temperatures with increasing external magnetic field. Conclusions. Strontium-substituted ferrimanganites of “heavy” lanthanides (Tm, Yb) are semiconductors, but at the same concentrations of diamagnetic ions the resistivity of “ilmenites” is several orders of magnitude higher than “perovskites”. In a magnetic field, the T$_{MI}$ temperature shifts to high temperatures, which leads to a “bipolar” magnetoresistance. The absolute value of $\delta$ reaches several tens of percent at temperatures close to room temperature.