Synthesis and Characterization of LaFeO3 Using High Energy Ball Milling

Abstract

In the Present work, lanthanum orthoferrite, LaFeO3 has been prepared using high energy ball milling (HEBM) of La2O3 and Fe2O3 oxide followed by thermal treatment. Prior to the ball milling, thermal studies of as mixed powder were carried out. The DTA study showed a three endotherm at 344°C, 495°C, and 680°C which is supported by weight loss from TGA. Further the as-mixed powder was milled for different duration, from 3 to 30 hours and heat treated at different temperature. The phase formation studies were carried out in the milled powders and heat treated powders. It was observed the phase formation temperature is about 1200 °C for unmilled samples. However, for milled samples, the phase formation takes place and much lower temperature irrespective to the milling time. A single phase LaFeO3 was obtained at 800°C for all milled samples. The Morphological study of LaFeO3, using SEM, reveals that the particles posses spherical symmetry with well uniformity. The average grain size of is found to be about 200nm. Moreover formation of clusters and aggregation also take place. The room temperature dielectric properties of pure LaFeO3 were measured in the frequency range from 20 Hz to 1MHz using LCR meter. It was found that the value of dielectric constant was high at lower frequency and decrease as the frequency increased and become almost constant at higher frequency region. The dielectric loss was found to be maximum at lower frequency.