Application of in-situ ion irradiation TEM and 4D tomography toadvanced scintillator materials

Scintillating nanomaterials are being investigated as replacements for fragile, difficult to synthesize single crystal radiation detectors, but greater insight into their structural stability when exposed to extreme environments is needed to determine long-term performance. An initial study using high-Z cadmium tungstate (CdWO4) nanorods and an in-situ ion irradiation transmission electron microscope (I3TEM) was performed to determine the feasibility of these extreme environment experiments. The I3TEM presents a unique capability that permits the real time characterization of nanostructures exposed to various types of ion irradiation. In this work, we investigated the structural evolution of CdWO4 nanorods exposed to 50 nA of 3 MeV copper (3+) ions. During the first several minutes of exposure, the nanorods underwent significant structural evolution. This appears to occur in two steps where the nanorods are first segmented into smaller sections followed by the sintering of adjacent particles into larger nanostructures. An additional study combined in-situ ion irradiation with electron tomography to record tilt series after each irradiation dose; which were then processed into 3D reconstructions to show radiation damage to the material over time. Analyses to understand the mechanisms and structure-property relationships involved are ongoing.