In order to examine whether the small-polaron theory can correctly describe motional behavior of light interstitials in metals at low temperatures, we have systematically investigated diffusion positive muons Al and doped with substitutional impurities various concentrations temperature range between 30 mK 100 K. pure ( 1 ppm overall impurity content) muon was found be mobile down mK. For Al, diffusional exhibits two regimes: (i) Above K maxima depolarization rate evolve, indicating a static...

Muon spin-rotation studies on the purest available samples of Al and Cu $\mathrm{Al}{\mathrm{Mn}}_{x}$ ($x=1300, 57, \mathrm{and} 42$ ppm) down to temperatures around 50 mK show that muons are delocalized in pure but increasingly localized with increasing Mn content. The temperature variations discussed terms strain localization trapping vicinity impurities. For Cu, partial delocalization is observed below 2 K, which probably limited by elastic strains from remaining

The influence of non-coaxial magnetic and electric fields on radioactive nuclei embedded as impurities in ferromagnetic materials is considered. attenuation factor G22(t), defined perturbed angular correlation theory [1], calculated for different angles ?0 between the directions field gradient ratios frequencies. method has been tested Cd gadolinium.

The diffusion and trapping of positive muons in aluminum has been studied using the method muon spin rotation. New measurements have performed on Al samples doped with Mg, Si, Ga, Ge impurities (which trap muons), for comparison also an Ag sample Er. Trapping rates site information were obtained temperatures between 0.05 50 K. A global fit to these earlier published data by other (Li, Mn, Ag) vacancies made it possible deduce temperature dependence intrinsic range 0.05--200 K compare...

We have investigated muon diffusion in niobium with controlled amounts of interstitial impurities. The polarization decay was interpreted terms a two-state model where the is alternatively state free or traps. A good fit all data obtained, yielding correlation times for jump motion, as well capture and release rates muons are found to be mobile NB down 14 K.

Neutron Compton scattering probes properties of matter at time scales the order 10−16-10−15 s. Very strong anomalies in cross-sections for protons were observed on NbHx and NbHxDy. The effective proton cross-section was found to vary with observation (first used as a parameter present experiments) being reduced by 30% times around 10−16 s but reaching its conventional value larger than 2·10−15 No explanation this anomaly (which indicates some kind very short-lived correlations) is known. A...

Several recent experiments on liquid and solid samples containing protons or deuterons have shown an interesting anomaly, which is apparently absent when the hydrogen isotopes are replaced by heavier particles. The anomaly a shortfall in intensity of energetic neutrons scattered samples; specifically, per isotope bulk smaller than for total scattering isolated isotope. Short-lived correlations spatial spin degrees freedom been proposed as explanation anomaly. involve entanglements created...

The authors have studied magnetic fluctuations in the paramagnetic phase of rare-earth-aluminium intermetallics type (RE)Al2 by method transverse-field muon spin rotation ( mu SR). In case with strong 4f exchange they could observe a increase damping SR signal on approaching Curie point Tc. One important contribution to increased rate is slowing down attributed formation correlations which are observed persist far above crystallographic site for + discussed as well hyperfine field induced at...

ZrV2 is an intermetallic compound with energetically different interstitial sites, which upon hydrogenation are successively filled hydrogen (thermodynamic distribution). When a positive muon added as microscopic probe, it thermalized at random and thus low temperatures statistically distributed over the available (unblocked) interstices. By varying preloading we scan accessible sites find that high content three kinds of interstices occupied, in contradiction to literature diffraction data....

Positive muons implanted in single-crystal Al doped with Mn are localized below 20 K contrast to the case of pure Al, where muon is completely delocalized down 1 K. Applying Anderson theory localization, we show consistently that a coherent tunneling state, which exists destroyed under influence lattice strains generated by impurities. Our data suggest strongly at tetrahedral sites 15

Combined magnetic and electric interaction is studied for cadmium in ferromagnetic gadolinium. The hyperfine field at 15 K determined to be - 327(8) kG its temperature dependence compared the magnetization nearest Gd atoms. angle β which forms with main component of gradient tensor found vary smoothly from ≈ 35° 0 = 0° Curie (293 K).

Mössbauer spectroscopic studies of the hexagonal antiferromagnet FeGe have been undertaken in temperature range 10-430 K. The variation magnetic hyperfine field for iron deviates from Brillouin function behaviour. From values B hf close to ordering critical exponent β=0.328 and Neél T N =398 K were obtained. similarity between isostructural binary compounds iron-germanium iron-tin systems as regards properties is stressed.

Several recent experiments on liquid and solid samples containing protons or deuterons show an interesting anomaly, which is a shortfall in the intensity of energetic neutrons scattered by samples. Previously we demonstrated that quantum correlations spatial spin degrees freedom hydrogen isotopes lead to entanglement scattering reduction intensity. The viability short-lived as cause observed anomalies further explored found be entirely feasible. General features basic premiss, reduces...