The term surface science is given to the complex and challenging interdisciplinary field focused on the chemical and physical interactions that take place at the interface between two phases, that is, solid-liquid, liquid-gas, solid-vacuum, solid-gas, etc.
When defining the boundary between two unlike phases, the terms “interface” and “surface” are used in a virtually interchangeable way. But there certainly lies a difference:
- “Surface” is a term that can be used to describe the interface that exists between matter and air/vacuum.
- “Interface” is a term that can be described as “the border between two spatial regions occupied by materials in different states,” that is, the juncture at which a solid and a liquid, or two solids, meet.
As a result, surface science studies dedicated to solid materials are generally performed using regulated vacuum conditions. In some ways, the development of contemporary surface science methods is fundamentally associated with the advent of high-vacuum and ultra-high vacuum (HV/UHV) processes.
This article analyzes the fundamentals and applications of surface science and focuses on HV/UHV studies.
A Short History of Surface Science
Surface science initially emerged in the 1970s as an intertwined discipline of physics and chemistry. Soon afterward, the procedure of depositing gaseous species onto metallic substrates underwent considerable innovations.
Gerhard Ertl, the Nobel Prize-winning chemist, had initially described the adsorption of hydrogen on palladium in 1974. Ertl’s study sheds light on heterogeneous catalysis and also on propelling studies of surface chemistry into a new era of quantitative observation. His study provided a better understanding of industrial, academic, and commercial processes, and laid the cornerstone for contemporary surface science.
In spite of Ertl’s research, it can be said that the history of surface science dates back even further. When high-purity vacuum conditions are absent, it can be very difficult and, at times, impossible, to correctly and precisely perform analysis of the chemistry and physics of solid surfaces. In his ground-breaking study on the adsorption of hydrogen, Ertl utilized low-energy electron diffraction (LEED), a method identified in 1927, almost five decades before his research.
This LEED technique was first believed to be unsuitable for applications related to surface science, considering that it utilized a collimated beam of low-energy electrons to view diffraction patterns as well as the intensities of electrons that are reflected off surfaces. Each one of these was exposed to interference caused by incident molecules inside the process atmosphere. In other words, LEED required more improved vacuum methods to reach the culmination of academic viability.
A breakthrough was made in the 1960s, with respect to high-vacuum technologies. This innovation successfully revealed a new pressure regime for industrial processing as well as academic research such as the ultra-high vacuum range, which reaches less than 10–9 mbar. Such an advancement within the field was crucial to Ertl’s work and has maintained its major impact on the broader field of surface science.
Surface Science: Nanoscale Chemistry and Physics
The scope of surface science goes beyond a broad range of academic fields, with real-world and commercial research applications.
The science of surfaces goes on, performed by scientists who study it under HV/UHV conditions to describe both the chemical and physical properties of different and various materials to provide an understanding of the diverse properties as given below:
- Quantum phenomena
- Electronic and optical
Analysis of these interfacial properties has provided a deeper insight into materials and technologies at the atomic level. Such an analysis has proven to be crucial, not least in the development of two-dimensional (2D) materials, clean fuel cells, new ecological processes, monomolecular materials, thin-film structures, organic photovoltaics, quantum computing, and much more.
HV/UHV Components for Surface Science Applications
Allectra provides high-technology solutions to both scientific and engineering markets, with a range of HV/UHV components optimized for surface science applications. The company has a robust history in terms of product development and revolutionary areas of research. It is ready to collaborate on customized product resolutions according to the vacuum needs of customers.
This information has been sourced, reviewed and adapted from materials provided by Allectra Limited.
For more information on this source, please visit Allectra.