Effect of sintering temperature on the structural, morphological, optical and electrical properties of Ba1 − xLaxFe12O19
K. R. Nishkala, Rajat Radhakrishna Rao, Srinivas Mutalik, M.S. Murari, Mamatha D. Daivajna
Abstract
Abstract La substituted M-type Barium hexaferrite, Ba (1−x) La (x) Fe 12 O 19 , (x = 0.25 and 0.30) were synthesized using ball milling followed by heat treatment at 1150˚C and 1300˚C and the influence of sintering temperature as well as La doping were presented. X-ray diffraction, FESEM, dielectric spectroscopy, and ferroelectric measurements were performed to study the structural, morphological, dielectric, and ferroelectric properties of the prepared samples. Rietveld refinement on the X-ray diffraction measurement reveals the formation of a phase magnetoplumbite structure of barium hexaferrite only for the samples sintered at 1300˚C. The secondary phase, along with the major magnetoplumbite structure, was observed for the sample sintered at 1150˚C. Hexagonal plate-like grains of different sizes were observed, and samples sintered at 1300˚C showed large-size grains. Porosity was observed to decrease with La doping. Impedance spectroscopy reveals that Maxwell-Wagner-type polarisation occurs with the relaxation of mobile charges having long-range hopping. However, the ferroelectric property was suppressed for samples sintered at 1300˚C.