The internal friction, the Young's modulus, and the heat flow were measured as a function of temperature (20–360K) at kHz frequencies in H-free and H-doped Ni50.8Ti49.2 alloys, mixed under vacuum and rapidly furnace cooled. The chemical H-diffusion coefficient DC was deduced from absorption experiments (323–1063K) and was compared with the Einstein diffusion coefficient DE derived from a Snoek (or Zener)-type relaxation PH. The comparison has allowed the interpretation of the so-called 200K relaxation as a Snoek (or Zener)-type relaxation due to H.

Hydrogen Diffusion and Interpretation of the 200K Anelastic Relaxation in NiTi Alloys. F.M.Mazzolai, B.Coluzzi, G.Mazzolai, A.Biscarini: Applied Physics Letters, 2004, 85[14], 2756-8