0000000000309014

AUTHOR

Puru Jena

showing 4 related works from this author

Effect of zero-point motion on the superconducting transition temperature of PdH(D)

1984

Using self-consistent density functional formalism we show that the electronic structure of PdH(D) is influenced by the zero-point vibration of hydrogen and deuterium. This quantum effect makes a small but significant contribution to the superconducting transition temperature ${T}_{c}$ of PdH(D). The reverse isotope effect on ${T}_{c}$ is found to be dominated by the changes in the force constants between PdH and PdD.

SuperconductivityPhysicsDeuteriumCondensed matter physicsTransition temperatureExcited stateKinetic isotope effectZero-point energyElectronic structureQuantum Hall effectAtomic physicsPhysical Review B
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Ferromagnetism in small clusters.

1991

Magnetization of small ferromagnetic clusters at finite temperatures has been studied using the Ising model and Monte Carlo techniques. The magnetization of finite clusters is reduced from the bulk value, and increases with the external magnetic field and with the cluster size. The results explain qualitatively the recent observations by de Heer, Milani, and Chatelain of the reduction with decreasing cluster size of the average magnetic moment in small iron clusters.

PhysicsMagnetizationFerromagnetismCondensed matter physicsMagnetic momentMonte Carlo methodCluster sizeGeneral Physics and AstronomyCurie temperatureIsing modelMagnetic fieldPhysical review letters
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Electronic Shell Structure and the Crystal Field Splitting in Simple Metals Clusters

1991

An upper limit for the number of atoms in metal clusters capable of exhibiting electronic shell structure has been estimated by comparing the energy difference between the highest occupied and the lowest unoccupied state with the crystal field splitting. The former is obtained by solving the Schrodinger equation for a spherical potential well with hard walls while the latter is obtained from the band structure of the solid. The results indicate that shell structures may persist in clusters containing as many as a million atoms.

Materials scienceCondensed matter physicsShell (structure)General Physics and AstronomyElectronic structureMolecular physicsSchrödinger equationsymbols.namesakeFourier transformCrystal field theoryPhysics::Atomic and Molecular ClusterssymbolsCluster (physics)Perturbation theoryElectronic band structureEurophysics Letters (EPL)
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Electronically induced trapping of hydrogen by impurities in niobium

1984

The binding energies of hydrogen and its isotopes to substitutional impurities Ti, Cr, and V in niobium have been calculated. The hydrogen-metal interaction is based on the effective-medium theory. The wave mechanics of the hydrogenic interstitials are explicity dealt with, and the lattice distortion created by the hydrogen is incorporated through the method of lattice statics. The difference in the electronic structure between impurity and host atoms is shown to be largely responsible for the binding of hydrogen to the impurities. The results are in agreement with recent inelastic neutron scattering experiments. Peer reviewed

Materials scienceHydrogenPhysicsNiobiumchemistry.chemical_elementTrappingNeutron scatteringchemistryImpurityCondensed Matter::SuperconductivityhydrogenPhysics::Atomic PhysicsAtomic physicsniobium
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