Relaxation of the spin of a positive muon in superconducting Nb3Al
Barsov S. G., Getalov A. L., Grebinnik V. G., Gordeev V. A., Gurevich I. I., Zhukov V. A., Kirillov B. F., Klimov A. I., Kruglov S. P., Kuz'min L. A., Lazarev A. B., Mikirtych'yants S. M., Mikhailov B. P., Nikol'skii B. A., Pirogov A. V., Ponomarev A. N., Selivanov V. I., Suetin V. A., Khlopkin M. N., Shcherbakov G. V.
The dipole relaxation rate σ has been measured for the spin of a positive muon in the superconducting state of the alloy Nb3Al at 12 K. The experimental time dependence of the muon polarization can be described well by the Kubo-Toyabe function describing the static distribution of the dipole magnetic fields of the nuclei in the Nb3Al crystal lattice in the absence of muon diffusion. The experimental value σ ~ 0.402 + 0.002//s~ 1 corresponds to an rms value ~ 8.2 Oe of the nuclear magnetic field at the muon.