THE RANGE OF EXCHANGE INTERACTIONS AND CURIE TEMPERATURE IN La0.67-xBixCa0.33MnO3 COMPOUNDS

Abstract

Magnetic properties of Bi 3+-doped La 0.67-x Bi x Ca 0.33 MnO 3(x = 0, 0.05, 0.1, 0.2) are investigated. Using the mean-field and ferromagnetic spin-wave theory at low temperatures, total exchange integrals and Curie temperatures are calculated in the range 0≤x≤0.2. Calculated values of Tc are in good agreement with those obtained by magnetic measurements. In addition, the total exchange integral decrease with Bi 3+ shows the existence of canted ferromagnetic order in the samples, as observed in experimental results.