TY - CONF A1 - Monks, Melissa-Jane A1 - Ritter, B. A1 - Würth, Christian A1 - Krahl, T. A1 - Kemnitz, E. A1 - Resch-Genger, Ute T1 - Rare earth strontium fluoride nanocrystals prepared via sol gel synthesis - Spectroscopic study of upconversion luminescence properties N2 - Obtaining high quality upconverting nanocrystals with only little crystal defects and hence, a high luminescence, affords a reliable synthesis route. Only this guarantees the reproducibility of the material and its spectroscopic properties required for future application. The fluorolytic sol-gel synthesis appears to be a convenient attempt, as this is a method with only few steps influencing the material properties, which can be well controlled. Also creating bright upconverting nanocrystals requires a profound understanding of the interplay of photophysical processes like multiphoton absorption, radiative and non-radiative pathways, and energy transfer in the material. Based on steady-state and time resolved luminescence measurements at different excitation power densities, the influence of the lanthanide doping ratio and synthesis parameters such as the annealing process on SrF2-nanocrystals obtained via the fluorolytic sol-gel synthesis was systematically studied. T2 - GDCh Wissenschaftsforum Chemie CY - Berlin, Germany DA - 10.09.2017 KW - Upconversion KW - Strontiumfluoride KW - Annealing study KW - Doping study KW - Luminescence PY - 2017 AN - OPUS4-42944 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Makris, Ruben A1 - Bronsert, Jeffrey A1 - Hille, Falk A1 - Kirschberger, D. A1 - Sowietzki, D. T1 - Crack Luminescence as innovative method for detection of fatigue damage N2 - Conventional methods of crack detection only provide a snapshot of the fatigue evolution at a specific location and in the moment of examination. The crack luminescence method realizes a clear visibility of the occurring cracks in loaded components during ongoing operation. Several different experiments show that due to the sensitive coating even the early stage of the crack formation can be detected what makes the crack luminescence helpful to determine the incipient crack opening behavior depending on load alternation. Due to the emitting of light under UV-radiation the crack gets clearly visible what makes continuous monitoring and automated crack detection possible. This can reduce costs and time needed for maintenance and inspection. T2 - Sensor +Test 2017 CY - Nuremberg, Germany DA - 30.05.2017 KW - Fatigue damage KW - Crack KW - Luminescence KW - Detection PY - 2017 AN - OPUS4-41839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -