TY - JOUR A1 - Giovannelli, F. A1 - Chen, Cong A1 - Díaz-Chao, P. A1 - Guilmeau, E. A1 - Delorme, F. T1 - Thermal conductivity and stability of Al-doped ZnO nanostructured ceramics N2 - Pure and Al-doped ZnO powders have been sintered by Spark Plasma Sintering. Al doping allows the ceramics to reach a relative density greater than 90% at a sintering temperature of 500°C. The morphology of powder nanoparticles impacts the final grain size of the sintered bulk compounds. A ceramic sintered from isotropic nanoparticles of 30 nm in diameter can reach an average grain size of 110 nm, whereas a ceramic sintered from platelets and isotropic nanoparticles exhibits an average grain size in the submicrometric range. The influence of ceramic grain size on the thermal conductivity has been investigated. It shows that substantial decrease of the grain size from several microns down to 100 nm reduces the thermal conductivity from 29.5 to 7.8 W/m K at 100°C. The stability of nanostructured ceramic has also been checked. After SPS, an annealing at 500°C in air also leads to grain growth. KW - Spark plasma sintering KW - Oxide KW - Thermal conductivity KW - Nanostructuring PY - 2018 DO - https://doi.org/10.1016/j.jeurceramsoc.2018.07.032 SN - 0955-2219 VL - 38 IS - 15 SP - 5015 EP - 5020 PB - Elsevier Science CY - Amsterdam AN - OPUS4-45740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Xue, Boyang A1 - Wang, Zhangjun A1 - Zhu, Tao A1 - Gu, Yezhen A1 - Sun, Weihong A1 - Chen, Chao A1 - Li, Zhigang A1 - Riedel, Jens A1 - You, Yi T1 - High repetition-rate laser-induced breakdown spectroscopy combined with two-dimensional correlation method for analysis of sea-salt aerosols N2 - Laser-induced breakdown spectroscopy (LIBS) offers a tantalizing glimpse into real-time, on-the-spot aerosol analysis. Yet, the reliance on traditional lasers, with their limitations in energy and frequency, hampers optimal sample handling, dissociation, and excitation. To address those challenges, we propose a novel tactic: utilize a high repetition-rate (rep.-rate) laser with low pulse energy in combination with the two-dimensional correlation (2D-corr.) technique for sea-salt aerosols analyses. By examining the emission patterns from both the laser pulse train and individual pulses, we recognize distinctive analyte-specific rep.-rate responses, which allowed spectral reconstruction of analytes, avoiding background interferences. This discovery enabled the rep.-rate modulation for a 2D-corr. spectroscopy workflow. Consequently, we successfully differentiated between particle-related and air-species-related spectral components, obviating expensive spectrometers or intensified image detectors. For instance, the Na I at 589 nm stemming from aerosols exhibited an entirely different correlation contribution compared to O I at 777 nm, resulting in reconstructed clean aerosol-spectra without spectral peaks originated from air species. This 2D-corr. aerosol LIBS approach shows promising analytical potential streamlining aerosol particle analysis. KW - LIBS KW - Aerosol PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613392 DO - https://doi.org/10.1016/j.sab.2024.107048 SN - 0584-8547 VL - 221 SP - 1 EP - 8 PB - Elsevier AN - OPUS4-61339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -