The diffusivity of this impurity in sintered Pb0.95Sr0.05(Ti0.47Zr0.53)-1wt%Nb2O5 was measured by using a tracer-sectioning method at between 600 and 1000C. It was found that the impurity had a very high diffusional mobility:

700-1000C:     D (cm2/s) = 1.0 x 10-1 exp[-140(kJ/mol)/RT]

M.V.Slinkina, G.I.Dontsov, V.M.Zhukovskii, R.R.Khafizov: Izvestiya Akademii Nauk SSSR - Neorganicheskie Materialy, 1990, 26[9], 1964-6. [Inorganic Materials, 1990, 26[9], 1677-9]