Coreexcited

Coreexcited refers to a state in atomic physics where an atom's inner-shell electron is promoted to a higher energy level, leaving a vacancy in the inner shell. This excitation occurs when an atom absorbs energy, typically from incoming photons or energetic electrons, that is sufficient to overcome the binding energy of the core electron.

Once a core vacancy is created, the atom is in an unstable, excited state. This vacancy is rapidly filled by an electron from an outer shell. As the outer shell electron transitions to the lower energy inner shell, it releases energy. This energy can be emitted as a photon (fluorescence) or transferred to another electron in the same atom, causing that electron to be ejected from the atom (Auger effect). The emitted photon or ejected electron carries information about the element and the specific electronic transitions involved.

Coreexcited states are fundamental to various spectroscopic techniques used for elemental analysis and chemical state determination. Techniques like X-ray photoelectron spectroscopy (XPS) and X-ray fluorescence (XRF) rely on the core excitation and subsequent relaxation processes to identify and quantify elements in a sample. The energies of the emitted photons or ejected electrons are characteristic of the element and its chemical environment, making these methods powerful tools in materials science, chemistry, and physics.