Editing Condensed matter physics (section)

===Magnetic resonance spectroscopy===
The [[local structure]], as well as the structure of the nearest neighbour atoms, can be investigated in condensed matter with magnetic resonance methods, such as [[electron paramagnetic resonance]] (EPR) and [[nuclear magnetic resonance]] (NMR), which are very sensitive to the details of the surrounding of nuclei and electrons by means of the  hyperfine coupling. Both localized electrons and specific stable or unstable isotopes of the [[Atomic nucleus|nuclei]] become the probe of these [[hyperfine structure|hyperfine interactions]]), which couple the electron or nuclear spin to the local  electric and magnetic fields. These methods are suitable to study defects, diffusion, phase transitions and magnetic order. Common experimental methods include [[nuclear magnetic resonance|NMR]], [[nuclear quadrupole resonance]] (NQR), implanted radioactive probes as in the case of [[muon spin spectroscopy]] (<math> \mu</math>SR), [[Mössbauer spectroscopy]], <math>\beta</math>NMR and [[perturbed angular correlation]] (PAC). PAC is especially ideal for the study of phase changes at extreme temperatures above 2000&nbsp;°C due to the temperature independence of the method.