MÖSSBAUER RELAXATION MEASUREMENTS ON Yb IN LaBel3 : INFLUENCE OF KONDO EFFECT AND SUPERCONDUCTIVITY

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-729-C8-730 ◽  
Author(s):  
P. Bonville ◽  
P. Imbert ◽  
G. Jéhanno ◽  
F. Gonzalez-Jimenez
Keyword(s):  
Kondo Effect ◽  
Relaxation Measurements

KONDO EFFECT AND LOCALIZED SPIN FLUCTUATIONS IN THE Zn-TRANSITION METAL SYSTEM

1971 ◽  
Vol 32 (C1) ◽  
pp. C1-221-C1-223
Author(s):  
P. J. FORD ◽  
C. RIZZUTO ◽  
E. SALAMONI ◽  
P. ZANI
Keyword(s):  
Transition Metal ◽  
Kondo Effect ◽  
Spin Fluctuations ◽  
Metal System ◽  
Transition Metal System

NMR studies of alkali intercalted carbon nanotubes

2003 ◽  
Vol 772 ◽  
Author(s):  
M. Schmid ◽  
C. Goze-Bac ◽  
M. Mehring ◽  
S. Roth ◽  
P. Bernier
Keyword(s):  
Carbon Nanotubes ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Energy Storage Devices ◽  
Nmr Studies ◽  
Storage Devices ◽  
Spin Lattice ◽  
Relaxation Measurements ◽  
Resonance Spin ◽  
Walled Carbon Nanotubes

AbstractLithium intercalted carbon nanotubes have attracted considerable interest as perspective components for energy storage devices. We performed 13C Nuclear Magnetic Resonance spin lattice relaxation measurements in a temperature range from 4 K up to 300 on alkali intercalated Single Walled Carbon Nanotubes in order to investigate the modifications of the electronic properties. The density of states at the Fermi level were determined for pristine, lithium and cesium intercalated carbon nanotubes and are discussed in terms of intercalation and charge transfer effects.

scholarly journals Renormalization of spin excitations and Kondo effect in open-shell nanographenes

2021 ◽  
Vol 104 (7) ◽  
Author(s):  
David Jacob ◽  
Ricardo Ortiz ◽  
Joaquín Fernández-Rossier
Keyword(s):  
Kondo Effect ◽  
Open Shell ◽  
Spin Excitations

Weak Kondo effect in the monocrystalline transition metal dichalcogenide ZrTe2

2021 ◽  
Vol 103 (17) ◽  
Author(s):  
Yihao Wang ◽  
Changzheng Xie ◽  
Junbo Li ◽  
Zan Du ◽  
Liang Cao ◽  
...  
Keyword(s):  
Transition Metal ◽  
Kondo Effect ◽  
Transition Metal Dichalcogenide

scholarly journals Intrinsically weak magnetic anisotropy of cerium in potential hard-magnetic intermetallics

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Anna Galler ◽  
Semih Ener ◽  
Fernando Maccari ◽  
Imants Dirba ◽  
Konstantin P. Skokov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnetic Anisotropy ◽  
High Performance ◽  
Kondo Effect ◽  
Quantitative Description ◽  
Many Body ◽  
Heavy Rare Earth Elements ◽  
Fe Intermetallics ◽  
Full Temperature

AbstractCerium-based intermetallics are currently attracting much interest as a possible alternative to existing high-performance magnets containing scarce heavy rare-earth elements. However, the intrinsic magnetic properties of Ce in these systems are poorly understood due to the difficulty of a quantitative description of the Kondo effect, a many-body phenomenon where conduction electrons screen out the Ce-4f moment. Here, we show that the Ce-4f shell in Ce–Fe intermetallics is partially Kondo screened. The Kondo scale is dramatically enhanced by nitrogen interstitials suppressing the Ce-4f contribution to the magnetic anisotropy, in striking contrast to the effect of nitrogenation in isostructural intermetallics containing other rare-earth elements. We determine the full temperature dependence of the Ce-4f single-ion anisotropy and show that even unscreened Ce-4f moments contribute little to the room-temperature intrinsic magnetic hardness. Our study thus establishes fundamental constraints on the potential of cerium-based permanent magnet intermetallics.

scholarly journals Kondo effect and superconductivity in niobium with iron impurities

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hansong Zeng ◽  
Dan Zhou ◽  
Guoqing Liang ◽  
Rujun Tang ◽  
Zhi H. Hang ◽  
...  
Keyword(s):  
Magnetic Moment ◽  
Low Temperatures ◽  
Kondo Effect ◽  
Film Structure ◽  
Kondo Temperature ◽  
Superconducting Transition ◽  
Interesting Phenomenon ◽  
Superconducting Device ◽  
Bcc Lattice ◽  
Device Applications

AbstractKondo effect is an interesting phenomenon in quantum many-body physics. Niobium (Nb) is a conventional superconductor important for many superconducting device applications. It was long thought that the Kondo effect cannot be observed in Nb because the magnetic moment of a magnetic impurity, e.g. iron (Fe), would have been quenched in Nb. Here we report an observation of the Kondo effect in a Nb thin film structure. We found that by co-annealing Nb films with Fe in Argon gas at above 400 $$^{\circ }$$ ∘ C for an hour, one can induce a Kondo effect in Nb. The Kondo effect is more pronounced at higher annealing temperature. The temperature dependence of the resistance suggests existence of remnant superconductivity at low temperatures even though the system never becomes superconducting. We find that the Hamann theory for the Kondo resistivity gives a satisfactory fitting to the result. The Hamann analysis gives a Kondo temperature for this Nb–Fe system at $$\sim $$ ∼ 16 K, well above the superconducting transition onset temperature 9 K of the starting Nb film, suggesting that the screening of the impurity spins is effective to allow Cooper pairs to form at low temperatures. We suggest that the mechanism by which the Fe impurities retain partially their magnetic moment is that they are located at the grain boundaries, not fully dissolved into the bcc lattice of Nb.

scholarly journals Evaluation of the Swallow-Tail Sign and Correlations of Neuromelanin Signal with Susceptibility and Relaxations

Tomography ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 107-119
Author(s):  
Tzu-Wei Lee ◽  
Cheng-Yu Chen ◽  
Kuan Chen ◽  
Chao-Wei Tso ◽  
Hui-Hsien Lin ◽  
...  
Keyword(s):  
Magnetization Transfer ◽  
Systematic Evaluation ◽  
Joint Analysis ◽  
Quantitative Susceptibility Mapping ◽  
Widespread Application ◽  
Hyperintense Signal ◽  
Significant Difference ◽  
Relaxation Measurements ◽  
Iron Deposits ◽  
Older Subjects

The presence of a swallow-tail sign in the nigrosome-1 with hyperintense signal shown on the susceptibility-weighted imaging (SWI) has been shown to be sensitive in detecting the abnormal iron deposits in this area. A systematic evaluation in healthy subjects is required before this tool can be recommended in a widespread application. We evaluated a simple and practical SWI approach using a multiecho gradient-echo sequence with an improved contrast-to-noise ratio (CNR). We also evaluated the association of the neuromelanin imaging contrast behavior with the susceptibility and relaxation measurements. Twenty-five older and 23 young healthy adults were evaluated. The CNRs of the nigrosome-1 were compared along with method and group. Correlations of the nigrosome-1 neuromelanin signal in the neuromelanin-sensitive imaging with CNRs in the susceptibility, T1 and T2 mappings were examined. Two different coils were used to confirm the reproducibility. Compared with the single-echo, multiecho SWI can improve the CNR of the swallow-tail sign. We found significant correlations between neuromelanin signal and CNRs in the susceptibility and T2 mappings, and T1 value. The older subjects exhibited increased CNRs compared with the young adults. No significant difference was observed in the measurements between 20 and 64 channels. The multiecho technique allows the high-quality nigrosome-1 images in SWI and allows for a joint analysis of T2* and quantitative-susceptibility mapping at high spatial resolution. The correlations of neuromelanin-sensitive imaging with susceptibility and T2 imply that the iron content in the nigrosome-1 may have significant influences on the hyperintensity of neuromelanin in the magnetization transfer-related contrast.

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