학술논문

Kinetics of the nitridation of dysprosium during mechanochemical processing.
Document Type
Article
Source
Journal of Alloys & Compounds. Jan2015, Vol. 620, p413-420. 8p.
Subject
*NITRIDATION kinetics
*DYSPROSIUM compounds
*MICROELECTROMECHANICAL systems
*CHEMICAL processes
*INORGANIC synthesis
Language
ISSN
0925-8388
Abstract
Dysprosium nitride was synthesized by the reactive milling of the rare earth metal under 400 kPa nitrogen gas in a planetary ball mill. The nitrogen consumption rate was calculated from in situ temperature and pressure measurements to find the reaction extent as a function of milling time at milling speeds from 350 to 650 rpm. The results are analyzed in terms of a fundamental milling dynamics model in which the input milling energy is the primary driving force for reaction and the rate limiting step of the nitridation kinetics is the formation of chemically active surfaces. The model differs from traditional gas–solid reactions which are often limited by diffusion of a species through a surface layer or by dissociation of the gas molecule. These results give fresh insight into reactive gas–solid milling kinetics. [ABSTRACT FROM AUTHOR]