Comprehensive study on Al3+doped Ba 0.9 La 0.1 Fe 12 O 19 hexaferrite: Structural, morphological, and electrical properties

The present work conducted a comprehensive study on the structural, microstructural, and electrical properties of Ba 0.9 La 0.1 Fe 12 O 19 hexaferrite doped with Al3+ ions. The Ba 0.9 La 0.1 Fe 12-x Al x O 19 system, with x = 0.0; 0.1; 0.3; 0.5; 0.7; 1.0, and 1.3 were prepared by ball milling assisted solid-state reaction method. The Rietveld method was utilized to refine the crystal structure, revealing an isostructural phase similar to a hexagonal magnetoplumbite mineral within the P63mc centrosymmetric space group (No-186). The lattice parameters (a, c , and V ) reach a minimum at x = 0.7 for Al3+ content, exhibiting similar behavior when considering the other space group P63/mmc. In addition, the crystalline size and microstrain, determined for the size-strain plot method (SSP), are 47.2-142 nm and 1.2 x 10-3 to 3.9 x 10-3, respectively. The micrographic images revealed clusters of particles with an average grain size ranging from 0.57 to 1.48 mu m. The AC conductivity remains constant at low frequencies, indicating the movement of long-range carriers. Dispersion at high frequencies results from electron hopping. The dielectric loss presented a low-frequency dispersion of the Maxwell-Wagner-type and dielectric relaxation at high frequencies. The study is important because it demonstrates the variation in the physical properties of doped barium hexaferrite.