Title of article :
Cr2O3-nucleated fine grained mono-mineral glass-ceramics of augite were produced from low-silica fly ash and additives of SiO2, Al2O3 and MgCO3, via two steps of heat treatment for nucleation and crystal growth. The starting glass approached the compositi
Author/Authors :
Yen-Pei Fu، نويسنده , , Dung-Shing Hung، نويسنده , , Chih-Wen Cheng، نويسنده , , Feng-Yi Tsai، نويسنده , , Yeong-Der Yao، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2009
Abstract :
The non-isothermal crystallization kinetics of Bi0.75Y2.25Fe5O12 powder prepared by coprecipitation has been investigated. The activation energy of crystallization was calculated by differential scanning calorimetry (DSC) at different heating rates. Analysis of non-isothermal DSC data presented values of 650 kJ/mol and 2.48 for the activation energy of crystallization and the Avrami exponent, respectively. This Avrami exponent value was consistent with surface and internal crystallizations occurring simultaneouly. The complex permittivity and permeability of Bi0.75Y2.25Fe5O12 were measured at X-band (8–12 GHz) by cavity perturbation technique. For dielectric properties, the real part of permittivity, ɛ′, was obtained in the range of 13.18–15.28. For magnetic properties, the real part of permeability, μ′, was obtained in the range of 12.21–20.98.
Keywords :
A. Powders: chemical preparation , C. Thermal properties , E. Soft magnets , C. Magnetic properties
Journal title :
Ceramics International
Journal title :
Ceramics International