Two recent material science examples of aluminum metaphosphate is as a host for transition metal phosphors in scintillation detectors.
Aluminum metaphosphate glass to detect ionizing X-ray radiation
Kei Kagami and coworkers (2018) developed a scintillation glass to detect ionizing X-ray radiation such as might be found in a medical setting. While single crystals have been used as phosphors for detection of ionizing X-ray radiation, glasses are more attractive because
- high transparency,
- low cost
- feasibility of large scale production
- easy to shape
- thermal, mechanical, and chemical stability
Glasses used as hosts for the phosphors include: silicates, borates, and phosphates. Phosphate glasses are preferable because:
- high thermal stability,
- high transparency
- low melting point
- high solubility of halide compounds and rare-earth ions
CsPO3-Al(PO3)3 as a host glass because phosphate glasses can easily dissolve halide compounds The phosphor, Ce3+, was chosen because of the high quantum efficiency of luminescence and fast decay attributed to the 5 d–4f transition.
Powders of CeH2PO4, Al(PO3)3 base and 1-10 mol % CeCl3∙7H2O dopant were placed in an alumina boat
- melted at 1000 °C in an electric furnacefor 30 min
- transferred to a stainless-steel plate at 300ºC
- quenched at a temperature below the glass transition temperature.
The authors reported glasses becoming yellow as the concentration of CeCl3 was increased.
Aluminum metaphosphate glass to detect nuclear fusion
A group of scientists from the FIREX project at the Institute of Laser Engineering, Osaka
University and the National Ignition Facility, Lawrence Livermore National Laboratory developed a glass to detect down-scattered neutrons, a diagnostic tool in neuclear fusion research.
This system uses an APLF80+3Pr glass scintillator pixel type array. The scintillation glass was prepared from:
- 20% Al(PO3)3, 99.99% pure
- 80% LiF, 99.99% pure
- 0-3% PrF3, 99.9% pure.
These materials, 8 – 80 g, were placed in a glassy carbon crucible with a lid and melted at at 1100°C for 0.5 – 1 h under nitrogen atmosphere. The glass melt was allowed to cool and anneal. Annealed glass was cut and polished.
Optical properties and structure of Pr3+-doped Al(PO3)3–LiF glasses as scattered neutron scintillator for nuclear fusion diagnostics T Murata, S Fujino, H Yoshida, Y Arikawa, T Nakazato, T Shimizu, N, Sarukura, M Nakai, T Norimatsu, H Azechi, K Kamada, Y Usuki, T Suyama, A Yoshikawa, N Sato8, H Kan
ICC3: Symposium 8: Glass-Science & Technology and Photonic Applications IOP Publishing IOP Conf. Series: Materials Science and Engineering 18 (2011) 112006
Photoluminescence and radiation response properties of CsPO3-Al(PO3)3-CeCl3-based glass scintillators
Kei Kagamia,∗, Yutaka Fujimotoa, Masanori Koshimizua, Daisuke Nakauchib, Takayuki Yanagidab, Keisuke Asaia. Optical Materials 87 (2019) 127–131