NRS

Nuclear resonant scattering (NRS) is an advanced spectroscopic technique that is used in condensed matter research to study electronic and magnetic properties of materials on atomic scales. The technique utilizes the high-brilliance X-rays produced by synchrotron radiation facilities to excite resonant states of atomic nuclei. NRS is considered the time-domain analog of traditional Mössbauer spectroscopy.

Working principle

Unlike traditional Mössbauer spectroscopy, which typically uses a radioactive source and operates in the energy domain, NRS uses pulsed synchrotron radiation. These X-ray pulses have very short duration (typically between 50 and 100 picoseconds) and possess a broad energy spectrum. This allows for the simultaneous excitation of all hyperfine-split nuclear resonances within a sample. Next, the nuclei decay coherently, and the interference between different energy transitions results in a temporal interference pattern known as quantum beats. These beats are analogous to the acoustic beats heard from slightly detuned tuning forks and contain information about the hyperfine fields acting on the nuclei.

Applications

NRS is used to study nanomagnetism in thin films, offering unique insights into depth-dependent spin structures and magnetic superstructures. Due to its high brilliance, it is also ideal for investigating materials under extreme conditions.