Synthesis, structural, dielectric and magnetic properties of hexagonal ferrites

Neodymium-substituted strontium hexa-ferrites Sr 0.5- x Nd x Co 0.5 Al 0.5 Fe 11.5 O 19 ( x = 0.0, 0.01, 0.03, 0.05) were synthesized by applying the Sol–gel scheme. The samples were characterized via X-ray diffraction, vibrating sample magnetometer and scanning electron microscopy. The XRD results exposed that the structure was a hexagonal type with some extra peaks and c/a ratio was less than 3.98 which confirmed the M-type hexagonal structure. From VSM results, it was perceived that saturation magnetization enlarged up to 0.01 then dropped with Nd concentration while the coercivity decreased up to 0.01 and then high by the substitution of Nd. SEM showed that grains were platelet-like and grain growth decreased with Nd concentration. Electrical properties were measured and it was observed that AC resistivity dwindled with rising temperature which showed that the material was like a semiconductor. These ferrites may be suitable for perpendicular recording media.