Methods of treating materials include providing positrons within the material and detecting radiation emitted upon annihilation of positron-electron pairs within the material while treating the material. Treating the material may include subjecting the material to one or more of a pressure change, a temperature change, and a change in atmosphere while detecting the radiation. Methods of characterizing materials include providing a material in a non-equilibrium state, detecting electromagnetic radiation emitted upon annihilation of positron-electron pairs within the material, and detecting a change in one or more physical or chemical characteristics of the material. Systems for treating materials include an enclosure, a positron-generating device for providing positrons within material to be treated within the enclosure, and a radiation detection device for detecting radiation emitted upon annihilation of positron-electron pairs.
 The United States Government has certain rights in this invention pursuant to Contract No. DE-AC07-05ID14517 between the United States Department of Energy and Battelle Energy Alliance, LLC.