Dielectric and magnetic properties of random and segregated ferrite polystyrene composites

Abstract

The dielectric and magnetic properties of polystyrene composites containing barium or nickel‐zinc ferrites were studied as function of the ferrite concentration and field frequency. The composites were prepared by methods yielding a random distribution of the ferrite particles or segregated structures. Barium ferrite‐poly‐styrene composites exhibited a typical insulator behavior, and only above 60% ferrite were high values of the dielectric properties noted at the lower frequencies, decreasing gradually with frequency to the low values typical of the higher frequencies. The mode of barium ferrite particle distribution did not affect the dielectric properties. The nickel‐zinc ferrite systems demonstrated a conductor type behavior. An apparent insulator‐conductor transition was observed, having lower values for segregated than for random distributions. The magnetic permability of barium ferrite‐polystyrene composites above 10% ferrite increases with the ferrite concentration, whereas the magnetic dissipation factor steeply increases with concentration above 40% ferrite.

Ferrite/Metal Composites Fabricated by Soft Solution Processing

“…), and polymer/magnetic metal nanocomposites (with metallic Fe, [26] Co, [27] maghemite, [28] and Fe 3 O 4 [29] ) within a polymer matrix. Macroscopic composites of 10±100 lm sized transition metal powders [30] and ferrites [31] have been fabricated in order to study their electrical and magnetic properties. A classification of nanostructure morphologies, according to the mechanism responsible for their magnetic properties, has been proposed.…”

Dielectric properties and morphology of polymer composites filled with dispersed iron

“…Metal–polymer composites have been the subject of extensive research 1–3. Considerable effort has been expended in the investigation of the structure–property relationship,4–9 at molecular and morphological level, which is necessary for designing new materials with desirable properties for specific technological applications 10–14…”

Dielectric losses in polyethylene/neodymium composites

“…The influence of nature, concentration and filler dimensions on the properties of polymer composites with conductive [15][16][17][18] or magnetic [14], [19][20] fillers was studied in several papers. It is shown that there is a critical concentration for that the percolation process occurs, leading to important variations of the electrical conductivity, permittivity and dielectric losses [14], [21][22] and magnetic properties [20].…”