**4. Conclusion**

Nanocrystalline LaFeO3 particles with an average diameter of 16 nm were prepared by using hot-soap technique. Crystalline LaFeO3 were formed at a relatively low heat-treatment temperature of 350°C without any phase segregation. This temperature was much lower than the combustion point of organic substances. With increasing the heat-treatment temperature, the grain size of LaFeO3 particles was increased. The LaFeO3 nanoparticles exhibited superparamagnetic behavior and had anomalous large net magnetization. The spontaneous magnetization reached the maximum when the precursor was heat-treated at 350°C. Moreover the particles exhibited the exchange bias properties with increasing the grain size of LaFeO3. The low blocking temperature observed by both magnetization and Mössbauer measurements indicated that the obtained nanoparticles at 350°C were magnetically isolated with each other.
