| Records |
| Author |
SERENI, J.G. |
| Title |
The role of “p-like†orbitals in Ce valence instabilities |
Type |
Journal Article |
| Year |
1985 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
Volume  |
47-48 |
Issue |
FEB |
Pages |
228-230 |
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| Abstract |
From the analysis of spectroscopical data of atomic Ce, the [f(dsp)] configuration is found to be the least energetic when the metallization enthalpy is taken into account. The p-character of the band in Ce IV compounds is discussed and the p-f hybridization proposed. |
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0304-8853 |
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ISI:A1985AKL5200061 |
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no |
| Call Number |
BT @ hernan @ |
Serial |
131 |
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| Author |
Kappler, J.P.; Besnus, M. J.; Beaurepaire, E.; Meyer, A.; Sereni, J.; Nieva, G. |
| Title |
Magnetic transition in the CePd3Bx system |
Type |
Journal Article |
| Year |
1985 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
JMMM |
| Volume |
47 |
Issue |
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Pages |
111-114 |
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| Abstract |
Susceptibility, high-field magnetisation, resistivity and heat capacity data for the CePd3Bx system are reported. The observed valence transition of Ce is the first example of a transition from an IV state system to a stable magnetic 4f1 state system, whose properties are tentatively ascribed to an aleatory cooperative state, due to the inhomogeneous character of the valence transition, rather than to a Kondo effect. |
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no |
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BT @ gnieva @ |
Serial |
422 |
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| Author |
Sereni, J.G.; Nieva, G.; Kappler, J.P. |
| Title |
ANOMALOUS CRYSTAL-FIELD EFFECTS IN THE SPECIFIC-HEAT OF CE-HEAVY FERMION COMPOUNDS |
Type |
Journal Article |
| Year |
1987 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
63-64 |
Issue |
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Pages |
101-103 |
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0304-8853 |
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ISI:A1987G356900031 |
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no |
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BT @ hernan @ |
Serial |
128 |
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| Author |
Sereni, J.G.; Nieva, G.; Huber, J.G.; Braun, E.; Oster, F.; Bruck, E.; Roden, B.; Wohlleben, D. |
| Title |
Evidence for 4f-instability of dilute terbium in thorium |
Type |
Journal Article |
| Year |
1987 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
63-64 |
Issue |
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Pages |
597-599 |
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We have measured the specific heat of dilute Th1?xTbx alloys (0.44 < x < 2.15 a/o), which rises linearly between 0.4 and 0.9 K with a slope of ?C/T ? 450 mJ/K2molTb followed by a Schottky anomaly with a maximum near 3.8 K. The high temperature ??T product was found to be 4% lower than that of Tb3+. The resistivity shows no minimum at low temperatures. Discussion is made in terms of non-integral valence of Tb. |
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0304-8853 |
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ISI:A1987G356900173 |
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no |
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BT @ hernan @ |
Serial |
129 |
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| Author |
Pureur, P.; Fraga, G. L.; Brandao, D. E.; Caudron,R.; Safa, H.; Nieva, G. |
| Title |
Specific heat measurements in scandium-rare earth anisotropic spin glasses |
Type |
Journal Article |
| Year |
1987 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
68 |
Issue |
2 |
Pages |
213-217 |
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We report on specific heat measurements at low temperature of the anisotropic spin glass alloys ScDy 3 at%, ScEr 4.25 at% and ScEr 10 at%. We find that at the lowest temperature range the data indicate the occurrence of an anisotropy induced gap around zero frequency in the density of states of the magnetic excitations. Moreover, some of our specific heat curves present a maximum coinciding with Tg, raising thus the question of thermal signs for a spin glass phase transition in anisotropic systems. |
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no |
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BT @ gnieva @ |
Serial |
425 |
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| Author |
KAPPLER, J.P.; SCHMERBER, G.; SERENI, J.G. |
| Title |
CERIUM MAGNETIC-BEHAVIOR IN CE(PD,M) WITH M = CO, NI, RH, IR, PT, CU, AG AND AU |
Type |
Journal Article |
| Year |
1988 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
76-7 |
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Pages |
185-186 |
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0304-8853 |
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ISI:A1988T046300057 |
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no |
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BT @ hernan @ |
Serial |
124 |
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Fraga, G.L.F.; Brandao, D.E.; Sereni, J.G. |
| Title |
Specific heat of X2MnSn (X = Co, Ni, Pd, Cu), X2MnIn (X = Ni, Pd) and Ni2MnSb Heusler compounds |
Type |
Journal Article |
| Year |
1991 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
102 |
Issue |
1-2 |
Pages |
199-207 |
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Results of low-temperature specific heat measurements (1.5-8.0 K) on X2MnSn (X = Co, Ni, Pd, Cu), X2Mnln (X = Ni, Pd) and Ni2MnSb Heusler compounds are presented. All the compounds, except the cobalt based one, exibit a lattice spectrum anomaly described by an Einstein's term (soft-phonons). For all but one compound, the experimental values of the electronic specific heat coefficients are, at least, twice as big as the theoretical estimates. For two compounds it was possible to determine the magnetic effective field on Mn nuclei. |
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0304-8853 |
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ISI:A1991GX03900034 |
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no |
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BT @ hernan @ |
Serial |
117 |
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| Author |
Pureur, P.; Sereni, J.G.; Schaf, J. |
| Title |
Specific heat and magnetic susceptibility in YNd alloys |
Type |
Journal Article |
| Year |
1992 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
104 |
Issue |
3 |
Pages |
1632-1634 |
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We report on the specific heat and dc magnetic susceptibility measurements of the YNd 4.5, 6.8 and 9.0 at % alloys. These systems present long-range SDW order just below the critical temperature. For temperatures well below T(C), the spin glass type of behavior is manifest. An interpretation is given in terms of a disorder- and frustration-induced breaking of the SDW coherence into small domains. |
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0304-8853 |
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| Notes |
ISI:A1992HH32800067 |
Approved |
no |
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BT @ hernan @ |
Serial |
115 |
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Sereni, J.G.; Trovarelli, O.; Schmerber, G.; Kappler, J.P. |
| Title |
Coexistence of magnetic order and heavy fermion behavior in Ce7X3 |
Type |
Journal Article |
| Year |
1992 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
108 |
Issue |
1-3 |
Pages |
183-184 |
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Low temperature specific heat and magnetic susceptibility measurements on Ce7X3 (X = Rh, Ni) compounds are reported. Ce7Rh3 shows an onset of spontaneous magnetization at 7.2 K. About 40% of the expected R ln 2 entropy gain is found in the paramagnetic phase, related to a gamma(HT) = 1.1 J/K2 mol specific heat coefficient. In Ce7Ni3 an antiferromagnetic transition is observed at 1.7 K, superimposed to a large C(p)/T electronic contribution, described by a gamma(HT) = 0.9 J/K2 mol coefficient for T > 10 K. These results are interpreted in terms of the three different crystal sublattices of Ce. The entropy gain related to each transition allows to identify the behaviour of each sublattice. In the case of Ce7Ni3 one sublattice behaves as a heavy fermion system, with a value of C(p)/T = 3.3 J/K2 Ce at. Such a behaviour is confirmed under an applied magnetic field. |
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0304-8853 |
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ISI:A1992HH32900075 |
Approved |
no |
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BT @ hernan @ |
Serial |
113 |
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KAPPLER, J.P.; SCHMERBER, G.; TROVARELLI, O.; SERENI, J.G. |
| Title |
HEAVY FERMION AND INTERMEDIATE VALENCE BEHAVIOR IN CE24CO11 |
Type |
Journal Article |
| Year |
1992 |
Publication |
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS |
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108 |
Issue |
1-3 |
Pages |
185-186 |
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Low temperature specific heat and magnetic susceptibility measurements on Ce24Co11 are reported. The electronic specific heat can be decomposed into two contributions: a low temperature one (arising at T < 5 K), with a maximum of 2.2 J/K mol at 0.9 K, and another one becoming dominant at T > 5 K, characterized by a gamma(HT) = 1.8 J/K2 mol efficient. The (chi)T product changes continuously with temperature, from 0.48 emu K/mol at 2 K to 7.85 emu K/mol at 200 K. Reminding that 1 mol = 1f.u. contains 24 Ce atoms distributed in ten unequivalent crystalline sites, we interpret the experimental results as due to: one atom which behaves as a heavy fermion, and the rest as intermediate valents, with a distribution of characteristic energies governed by nine different environments. The specific heat behaviour under applied field confirms this interpretation. |
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0304-8853 |
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ISI:A1992HH32900076 |
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no |
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BT @ hernan @ |
Serial |
114 |
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