PHASE EQUILIBRIA

Phase Equilibria

Traditional introductory materials science texts usually cover the topic of phase equilib- 

ria adequately for understanding electronic materials. The main reason is based on the 

fact that most introductory materials science texts emphasize metallurgical materials, 

namely metals and alloys, even though these texts have often been modernized with the 

addition of polymers and electronic materials. Metallurgy deals extensively with mixed 

composition alloys such as steel. An understanding of steel and other important alloys 

requires a detailed knowledge of the phase diagram for the system, in order to know 

under what conditions to expect certain alloy phases and the composition of the phases. 

However, oftentimes advanced physics and chemistry courses spend little time on this 

topic, and while some forms of phase equilibrium are covered in undergraduate chem- 

istry courses, solid state phase diagrams are often barely mentioned. It is clear, however, 

that modern trends in materials science and electronic materials science include complex 

materials that can have several phases and wide homogeneity (stoichiometry) ranges. 

Included in the kinds of electronic and photonic materials in which phase equilibria are 

important are modern binary semiconductors that are used extensively for both elec- 

tronic and optical devices, ceramic superconductors, alloy superconductors, magnetic 

alloys, high dielectric constant insulators, and polymer blends. 

In Chapter 6 on phase equilibria we provide simple derivations of the Gibbs phase 

rule and the lever rule and outlines the procedure to estimate phase diagrams from known 

thermodynamic data. All materials scientists deal with the formation of phases from 

some primal state, and hence often the initial stage of phase formation, nucleation 

becomes important in determining final product morphologies. For this reason nucle- 

ation is added in the chapter.An understanding of nucleation phenomena is also impor- 

tant to the understanding of the processes that are used to prepare the thin films used 

for most modern electronic and optical devices. 

Ramon A Carmona C.

C.I 17646653

CRF

http://media.wiley.com/product_data/excerpt/71/04716959/0471695971.pdf

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