Magnetic and transport properties of La0.8Ca 0.2MnO3 nanoparticles with average size of 18 nm and Curie temperature TC ≈ 231 K have been studied. Pronounced irreversibility of magnetization below Tirr ≈ 208 K has been observed. Studied particles have shown memory effects in zero-field-cooled and field-cooled magnetization. The resistivity has a semiconducting character at 150 < T < 300 K and exhibits relaxation and memory effects below the Curie temperature. The results suggest that superspin-glass features in ensembles of interacting 18 nm La0.8Ca0.2MnO3 particles appear along with superferromagnetic-like features.
- Size effect