5 citations · 32 across the 20 of their papers we have counts for
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Temperature dependence of the magnetic hyperfine field at an s-p impurity diluted in Ni
A. L. de Oliveira, C. M. Chaves, N. A. de Oliveira +1
We study the formation of local magnetic moments and magnetic hyperfine fields at an \textit{s-p} impurity diluted in intermetallic Laves phases compounds Ni ( = Nd, Sm…
Pseudogap and the specific heat of high T superconductors: a Hubbard model in a n-pole approximation
E. J. Calegari, A. C. Lausmann, S. G. Magalhaes +2
In this work the specific heat of a two-dimensional Hubbard model, suitable to discuss high- superconductors (HTSC), is studied taking into account hopping to first () and…
Interplay between condensation energy, pseudogap and the specific heat of a Hubbard model in a n-pole approximation
A. C. Lausmann, E. J. Calegari, S. G. Magalhaes +2
The condensation energy and the specific heat jump of a two-dimensional Hubbard model, suitable to discuss high- superconductors, is studied. In this work, the Hubbard model i…
Specific heat of a non-local attractive Hubbard model
E. J. Calegari, C. O. Lobo, S. G. Magalhaes +2
The specific heat of an attractive (interaction ) non-local Hubbard model is investigated. We use a two-pole approximation which leads to a set of correlation functions. In pa…
Pseudogap and the specific heat of high superconductors
E. J. Calegari, S. G. Magalhaes, C. M. Chaves +1
The specific heat of a two dimensional repulsive Hubbard model with local interaction is investigated. We use the two-pole approximation which exhibits explicitly important correla…
Magnetic moment formation at a dilute Ce(140) impurity in RCo_2 compounds
A. L. de Oliveira, C. M. Chaves, N. A. de Oliveira +1
A great deal of experimental work using perturbed angular correlation (PAC) has succeed in measuring hyperfine fields in Ce diluted in metallic systems, thus allowing the determina…
Magnetic hyperfine field at \textit{s-p} impurities on Laves phase compounds
C. M. Chaves, A. L. de Oliveira, N. A. de Oliveira +1
Recent experimental results for the magnetic hyperfine field B_{\rm hf} at the nuclei of \textit{s-p} impurities such as Sn in intermetallic Laves phases RM_2 (R = Gd, Tb…
Superconductivity in an extended Hubbard model with attractive interaction
E. J. Calegari, S. G. Magalhaes, C. M. Chaves +1
In this work, a two-dimensional one-band Hubbard model is investigated within a two-pole approximation. The model presents a non-local attractive potential that allows th…
Effect of hybridization on the magnetic properties of correlated two-band metals
C. M. Chaves, A. Troper
The magnetic properties of transition-like metals are discussed within the single site approximation, which is a picture to take into account electron correlations. The metal is de…
Model for spin coupling disorder effects on the susceptibility of antiferromagnetic nanochains
C. M. Chaves, Thereza Paiva, J. d'Albuquerque e Castro +1
The temperature dependence of the static magnetic susceptibility of exchange-disordered antiferromagnetic Heisenberg spin-1/2 finite chains with an odd number of spins is investiga…
Ferromagnetism in two band metals: Combined effect of Coulomb correlation, hybridization and band widths
C. M. Chaves, A. Troper
We study the possibility of ferromagnetism in metals. The metal is described by two hybridized bands one of which includes Hubbard correlation whereas the other is uncorrelated. We…
Cross effect of Coulomb correlation and hybridization in the occurrence of ferromagnetism in two shifted band transition metals
C. M. Chaves, A. Troper
In this work we discuss the occurrence of ferromagnetism in transition-like metals. The metal is represented by two hybridized() and shifted ) bands one of which includes…
On the use of a single site approximation to describe correlation in pure metals
C. M. Chaves, A. A. Gomes, A. Troper
The magnetic properties of pure transition-like metals are discussed within the single site approximation, to take into account the electron correlation. The metal is described by…
Specific heat in different magnetic phases of RNi2B2C (R= Gd, Ho, Er): theory and experiment
M. ElMassalami R. M. Saeed, C. M. Chaves, H. Takeya +3
The borocarbides RNi2B2C (R=Gd, Ho, Er) exhibit a large variety of magnetic states and as a consequence rich phase diagrams. We have analyzed the nature of these states by specific…
On the ferromagnetic structure of the intermetallic borocarbide TbCo2B2C
M. ElMassalami, R. Moreno, R. M. Saeed +5
Based on magnetization, specific heat, magnetostriction, and neutron diffraction studies on single-crystal TbCo2B2C, it is found out that the paramagnetic properties, down to liqui…