DIELECTRIC-PROPERTIES OF HEXAGONAL FERRITES

Dielectric properties of hexagonal ferrites BaFe//1//2O//1//9, BaTi//2Fe//4O//1//1, and BaSn//2Fe//4O//1//1 are examined from 4. 2 to 500 K. BaFe//1//2O//1//9 shows low dielectric constant and conductivity, while BaTi//2Fe//4O 1//1 shows large dielectric constant and conductivity. BaSn//2Fe//4O//1//1, which has the same crystal structure as BaTi//2Fe//4O//1//1, exhibits very low dielectric constant and conductivity. Ti ions seem to make a large difference in dieletric and electronic properties in these ferrites. Three kinds of dielectric relaxations are found in BaTi//2Fe//4O//1 at about 30, 290, and 433 K. The first arises from electron transfer between cations, the second from the Maxwell-Wagner interfacial polarization, and the third from cation diffusion.