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1.
Martyn C. R. Symons 《Hyperfine Interactions》1984,19(1-4):771-783
High energy muons induce radiation damage when they interact with molecules or ions. The chemical reactions expected to occur are summarised, and attention is then given to events likely to give rise to radicals exhibiting muon-electron hyperfine coupling. Addition of muonium atoms to double or treble bonds, which is one example of the way this can occur is considered, and, in particular, the resulting proton-muon hyperfine isotope effect is discussed. Finally, possible chemical models for paramagnetic muon centres in carbon and silicon are outlined.I thank Dr. S. Cox and Dr. A. Hill for helpful discussions. 相似文献
2.
K. Nagamine 《Hyperfine Interactions》1979,6(1-4):347-355
Experimental advances in solid state physics research using polarized negative muons (in the ground state of muonic atoms) are reviewed. The main subject is studies of – hyperfine interactions in magnetic materials. Basic principles and distinctive features of the –SR method are also presented, and possible future developments are briefly discussed. 相似文献
3.
The method of μSR is briefly described and its potential in the field of solidstate physics (especially metal physics) is
discussed. Some examples from the fields of magnetism, spin relaxation and particle diffusion in metals are shown and comparisons
with conventional hyperfine interaction methods are made for some areas of application. 相似文献
4.
M. Gladisch D. Herlach H. Metz H. Orth G. zu Putlitz A. Seeger H. Teichler W. Wahl M. Wigand 《Hyperfine Interactions》1979,6(1-4):109-112
By means of the muon spin rotation technique (+SR), the temperature dependence of the magnetic field inside the normal-conducting domains of high-purity tantalum crystals in the intermediate state has been measured in the temperature range 2.36K+SR. Possible applications of these findings to the study of long-range diffusion of positive muons at low temperatures are indicated. 相似文献
5.
Ch. Niedermayer C. Bernhard J.L. Tallon G.V.M. Williams J.I. Budnick E.J. Ansaldo C.E. Stronach D.R. Noakes C. Bucci R. De Renzi G. Guidi 《Hyperfine Interactions》1997,105(1-4):139-144
Muon‐spin‐rotation studies on a variety of polycrystalline cuprate high‐T_ c superconductors reveal a generic dependence of
the superconducting transition temperature T_ c upon condensate density throughout the entire range of hole doping. Upon full
oxygenation the CuO chains in YBa2Cu3O7-\delta become metallic and superconducting and the condensate density is dramatically enhanced. The very rapid suppression of the
condensate density n_ s upon Zn substitution in YBa2(Cu1-xZnx)3O6+\delta is inconsistent with s‐wave pairing and magnetic scattering but points towards a d‐wave pairing state with non‐magnetic scattering
in the unitarity limit.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
J. Major J. Mundy M. Schmolz A. Seeger K. -P. Döring K. Fürderer M. Gladisch D. Herlach G. Majer 《Hyperfine Interactions》1986,31(1-4):259-264
Spin precession of positive muons in chromium in zero applied magnetic field is reported for the first time. The observations
cover the temperature range from about 2.5 K to 10 K and thus pertain to the so-called longitudinal spin-density wave (LSDW)
state of antiferromagnetic Cr. The conclusions that may be drawn from the existence of one rather sharp spin precession line
are discussed, among them the estimateD
μ=2.4·10−14 m2 s−1 for the muon diffusivity at 4 K. Considerable evidence exists for a strong interactions of μ+ with the charge-density waves that are likely to accompany the LSDWs in Cr. 相似文献
7.
We report on the development of a spectrometer for Muon Spin Rotation based on multiwire proportional chambers. The coordinates provided by telescopes each composed of two chambers are used to reconstruct the muon and the positron trajectories in
+
e++ve+
decay. A real-time analysis program verifies that the two tracks intersect within the target: this constitutes a very stringent test to veto events which do not correspond to a muon decay. The results of some experiments are given in order to illustrate the field of application of this spectrometer. 相似文献
8.
Sonier JE Huang W Kaiser CV Cochrane C Pacradouni V Sabok-Sayr SA Lumsden MD Sales BC McGuire MA Sefat AS Mandrus D 《Physical review letters》2011,106(12):127002
It is shown that attempts to accurately deduce the magnetic penetration depth λ of overdoped BaFe(1.82)Co(0.18)As? single crystals by transverse-field muon spin rotation (TF μSR) are thwarted by field-induced magnetic order and strong vortex-lattice disorder. We explain how substantial deviations from the magnetic field distribution of a nearly perfect vortex lattice by one or both of these factors is also significant for other iron-arsenic superconductors, and this introduces considerable uncertainty in the values of λ obtained by TF μSR. 相似文献
9.
Dunsiger SR Aczel AA Arguello C Dabkowska H Dabkowski A Du MH Goko T Javanparast B Lin T Ning FL Noad HM Singh DJ Williams TJ Uemura YJ Gingras MJ Luke GM 《Physical review letters》2011,107(20):207207
Theory predicts the low temperature magnetic excitations in spin ices consist of deconfined magnetic charges, or monopoles. A recent transverse-field (TF) muon spin rotation (μSR) experiment [S.?T. Bramwell et al., Nature (London) 461, 956 (2009)] reports results claiming to be consistent with the temperature and magnetic field dependence anticipated for monopole nucleation-the so-called second Wien effect. We demonstrate via a new series of μSR experiments in Dy(2)Ti(2)O(7) that such an effect is not observable in a TF μSR experiment. Rather, as found in many highly frustrated magnetic materials, we observe spin fluctuations which become temperature independent at low temperatures, behavior which dominates over any possible signature of thermally nucleated monopole excitations. 相似文献
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11.
V. P. Michal 《Journal of Experimental and Theoretical Physics》2012,115(5):849-853
The formalism for analyzing the magnetic field distribution in the vortex lattice of Pauli-limit heavy-electron superconductors is applied to the evaluation of the vortex lattice static linewidth relevant to the muon spin rotation (??SR) experiment. Based on the Ginzburg-Landau expansion for the superconductor free energy, we study the evolution with respect to the external field of the static linewidth both in the limit of independent vortices (low magnetic field) with a variational expression for the order parameter and in the near H c2 P (T) regime with an extension of the Abrikosov analysis to Pauli-limit superconductors. We conclude that in the Ginzburg-Landau regime in the Pauli-limit, anomalous variations of the static linewidth with the applied field are predicted as a result of the superconductor spin response around a vortex core that dominates the usual charge-response screening supercurrents. We propose the effect as a benchmark for studying new puzzling vortex lattice properties recently observed in CeCoIn5. 相似文献
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13.
A. Lappas K. Prassides A. Amato R. Feyerherm F. N. Gygax A. Schenck 《Zeitschrift für Physik B Condensed Matter》1994,96(2):223-226
We report a muon spin rotation (SR) study of the magnetic properties of the Cu2+ quasi-one-dimensional CuGeO3 system and its lightly-doped derivative Cu0.97Zn0.03GeO3. Susceptibility measurements on CuGeO3 show a sudden change in the vicinity of 14 K that has been interpreted before as a magnetic transition to a spin-Peierls state. SR shows no evidence of spin freezing below 14 K, implying that the transition is to a magnetic state with no static (random or ordered) electronic moments. A modest slowing down of the electronic spin dynamics is also identified at this temperature. Similarly, no evidence of a transition to a static magnetic state is found for Cu0.97Zn0.03GeO3 whose susceptibility shows hysteretic behaviour between zero-field and field cooled measurements at 4 K, previously ascribed to spinglass-like behaviour. Given the nature of the muon spin as a local magnetic probe, the present results necessitate a re-interpretation of the origin of the susceptibility anomaly observed in the doped system. 相似文献
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16.
Kadono R Shimomura K Satoh KH Takeshita S Koda A Nishiyama K Akiba E Ayabe RM Kuba M Jensen CM 《Physical review letters》2008,100(2):026401
We have detected the occurrence of hydrogen bonding involving an interstitial positive muon situated between hydrogen atoms of two independent alanate anions in sodium alanate (NaAlH4). Ti doping, which is known to dramatically improve the hydrogen cycling performance of NaAlH4, reduces the kinetic barrier of the transition of the muon from the muon-dialanate state to a mobile interstitial state. This observation strongly suggests that hydrogen bonding is the primary bottleneck for hydrogen release or uptake in sodium alanate, which might be common to other complex hydrides. 相似文献
17.
Diamagnetic muon spin resonance experiments were carried out in a-quartz at two temperatures: 300 K and 130 K. A strong diamagnetic resonance peak was observed at both temperatures. The spectrum exhibits an anisotropy in the chemical shift of 15 ppm (300K) and 25 ppm (130K). 相似文献
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19.
A. Golnik W. Wałecki A. Wedinger J. A. Gaj E. Recknagel 《Hyperfine Interactions》1989,51(1-4):1087-1090
Spin fluctuations in Cd1−xMnxTe (x=0.05, 0.10, 0.20, 0.30, 0.40, 0.54, 0.60, 0.68) were studied by the muon spin rotation (μSR) technique. Correlation times
of the Mn-spins are deduced from the muon depolarization rates. A strong increase of the depolarization rate near the Mn-spin
freezing temperature is observed. At 88 K, larger depolization rates are found forx=0.10 andx=0.20 than for higher Mn-concentrations, indicating that the exchange narrowing is considerably reduced (spin fluctuations
slow down) for lower Mn-concentrations. 相似文献
20.
R. F. Kiefl 《Hyperfine Interactions》1993,80(1-4):1181-1193
In non-metallic solids the positive muon often forms paramagnetic muonium centers which are characterized by the hyperfine interactions of the unpaired electron with the positive muon and with the surrounding nuclear spins. The static and fluctuating components of these hyperfine interactions provide information on local molecular dynamics and local electronic structure. Some recent results on C60 and related compounds are presented to illustrate this. 相似文献