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Table 2 Positron trapping modes and free-volume nanopore parameters related to o-Ps decaying determined from four-term decomposed PAL spectra of MgO-Al2O3 ceramics sintered at different T s temperatures

From: Water-Vapor Sorption Processes in Nanoporous MgO-Al2O3 Ceramics: the PAL Spectroscopy Study

Sample Positron trapping modes Free-volume parameters
τ av, ns τ b, ns κ d, ns−1 R 3, nm ~f 3, % R 4, nm ~f 4, %
T s = 1100 °C
  Initial drying 0.254 0.21 1.10 0.309 0.38 1.844 11.75
  Water vapor 0.263 0.21 1.15 0.271 0.66 1.539 2.43
  Final drying 0.257 0.21 1.08 0.307 0.46 1.810 8.36
T s = 1200 °C
  Initial drying 0.232 0.19 0.94 0.319 0.26 1.852 9.62
  Water vapor 0.252 0.21 1.19 0.293 0.72 1.636 1.16
  Final drying 0.229 0.19 0.93 0.296 0.61 1.821 7.77
T s = 1300 °C
  Initial drying 0.197 0.17 0.66 0.325 0.20 1.818 6.18
  Water vapor 0.213 0.19 0.80 0.340 0.52 1.630 2.40
  Final drying 0.198 0.17 0.63 0.327 0.20 1.807 6.06
T s = 1400 °C
  Initial drying 0.178 0.16 0.44 0.331 0.19 1.701 3.07
  Water vapor 0.211 0.18 0.78 0.335 0.63 1.613 1.74
  Final drying 0.179 0.16 0.40 0.334 0.19 1.692 3.02