Thermodynamic and Electrophysical Properties of Nanosized LaMeFeCrMnO6.5 (Me = Li, Na, K) Ferro-Chromo-Manganites

Resumo

Ferro-chromo-manganites with compositions LaMeFeCrMnO_6.5 (Me = Li, Na, K) are synthesized via ceramic technology from La₂O₃ (special purity grade), Fe₂O₃, Cr₂O₃, Mn₂O₃, and carbonates of alkali metals (analytical grade). The individuality of the resulting compounds is confirmed via X-ray phase analysis. The heat capacity of nanosized LaMeFeCrMnO_6.5 (Me = Li, Na, K) ferro-chromo-manganites is measured via dynamic calorimetry in the temperature interval of 298.15–673 K on an IT-S-400 apparatus. The values of C°_p(T) and thermodynamic functions H°(T)–H°(298.15), S°(T), and Φ^xx(T) are calculated. The temperature dependences of the electrical capacity (C), dielectric permeability (ε) and electrical resistivity (R) studied in the temperature range of 293–483 K show that these materials are also of interest for microelectronics.