Syed Qamar Abbas Shah will present his comprehensive exam topic, “Surface Segregation: Thermodynamics and Experimental Investigation” in person.

Abstract: Surface segregation is a phenomenon observed at material surfaces and interfaces, wherein specific atoms migrate from the bulk toward the surface to form enriched layers. This migration, primarily governed by differences in surface energy, seeks to minimize the material’s overall Gibbs free energy. Understanding surface segregation is pivotal, given its wide-range implications across materials science, catalysis, and semiconductor technology impacting mechanical, electrical, and catalytic properties. The comprehension of thermodynamic parameters dictating segregation behavior within binary alloy systems, alongside the investigation of experimental techniques elucidating segregation mechanisms, holds paramount significance for refining material properties. The study aims to delve into the thermodynamic principles and experimental methodologies underpinning surface segregation. By exploring thermodynamic parameters, equilibrium criteria, and alterations in surface tension, we aim to uncover the driving forces behind this phenomenon. Additionally, we will discuss the utilization of X-ray photoemission spectroscopy (XPS) depth profiling to calculate the change in Gibbs free energy and the surface free energy of segregating atoms in the binary alloy system under constant temperature and pressure conditions.