MUON DIFFUSION AND TRAPPING STUDIES IN HIGH-PURITY VANADIUM

We present the first results of a study of the effects of varying impurity concentration on the temperature dependence of the depolarization rate of positive muons implanted into vanadium. Data are reported for the most highly purified polycrystalline sample yet measured, and the same sample subsequently doped with about 500 ppm oxygen by weight. The data for the pure sample shows a low depolarization rate (<.15 μsec-1) at all temperatures measured, showing a broad minimum centered at ∼35 K, followed by a sharp peak near 90 K and a rapid drop to negligible values at 200 K. The data is contrasted with previously published data [2] on less pure samples, and calls into question previous interpretations of the behavior of the μ+ at low temperatures in impure vanadium [1] as one-phonon-assisted tunneling. © 1979 North-Holland Publishing Company.