Vaporization and Diffusion of Manganese–Zinc Ferrite

✍ Scribed by Hideaki Inaba; Tsuneo Matsui

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 230 KB
• Volume: 121
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1996.0021

✦ Synopsis

important to know the behaviors of the vapor and of the diffusing species of the solid using the same sample. Since Vaporization and diffusion of Mn-Zn ferrite were studied for both powdered and bulk sintered samples by a mass-spectro-the dynamic vaporization and diffusion behavior of metric method and EPMA analysis. Equilibrium vapor pres-Mn-Zn ferrits is considered to depend on the size and sures were obtained using the powdered sample and the preshape of sample, it is desirable to use both the powdered dominant vapor species was Zn(g) with small fractions of sample and the bulk sintered samples for vaporization and FeO(g) and MnO(g). Over the bulk sintered sample, the vapor diffusion studies.

pressures of Zn(g), FeO(g), and MnO(g) exponentially de-

In this study, vaporization has been studied for both the creased with time and approached finite values. The surface powdered and the bulk sintered samples and diffusional was depleted severely with Zn atoms and slightly with O atoms analysis in relation to the vaporization kinetics has been while it was enriched with Mn and Fe atoms. The diffusion made for the latter sample.

equation is solved for the Zn profile using the time-dependent boundary condition of the surface, and the diffusion profile of II. EXPERIMENTAL PROCEDURE Zn is analyzed. The activation energy of diffusion obtained is 410 kJ mol ؊1 , which is about three times larger than the literature value obtained by the tracer method.