Crystallization Kinetics and Microwave Properties of Bi^sub 0.5^Y^sub 2.5^Fe^sub 5^O^sub 12^ Via the Coprecipitation Process

The crystallization kinetics of Bi...Y...Fe...O... powders prepared by the coprecipitation process have been investigated. The activation energy of crystallization was calculated on the basis of differential scanning calorimetry at different heating rates. Analysis of nonisothermal DSC data yielded a value of 823.8 kJ/mol and 2.25 for the activation energy of crystallization and the Avrami exponent, respectively. This value for the Avrami exponent was consistent with surface and internal crystallization occurring simultaneously. The complex permittivity and permeability of Bi...Y...Fe...O... was measured at the X-band (8-12 GHz) using the cavity perturbation technique. For dielectric properties, the real part of permittivity, ...', was obtained in the range of 13.57-16.37. For magnetic properties, the real part of permeability, ...' ,was obtained in the range of 21.61-16.90. (ProQuest: ... denotes formulae/symbols omitted.)