Quantitative analysis of proton solubility in YSZ using SIMS

Abstract The solubilities of protons in 8YSZ single crystal and polycrystals at 600 °C were investigated using secondary ion mass spectrometry (SIMS). As a measure of proton solubility, deuteron solubility in YSZ was measured because of its lower background level in SIMS measurements. It became possible to quantitatively determine the solubility using a new analytical method proposed here, which includes a procedure to remove the small background signal included in the deuterium signal. The new method was employed for determining the solubilities in YSZ single crystal and polycrystals. Although the solubility in the single crystal was below the detection limit of SIMS (~1016 cm−3), the solubilities in the polycrystals were significantly larger than that in the single crystal. The solubility shows a proportional relationship with the grain boundary density, which strongly suggests that deuterons incorporate mainly into the grain boundaries in YSZ. The deuteron solubility per unit grain boundary area was determined to be 3.2 × 1013 cm−2.