What is X-ray absorption spectroscopy?

X-ray absorption spectroscopy (XAS) is a technique used to determine the local atomic structure and electronic states of materials. It involves measuring the absorption of X-rays by a sample as a function of energy. By analyzing the resulting spectrum, information about the elemental composition, chemical bonding, and coordination environment of specific atoms within the material can be obtained. XAS is commonly used in various fields, including chemistry, physics, materials science, and environmental science, to study the structure and properties of materials at the atomic level.