|   | 
Details
   web
Records
Author Braghta, A.; Schmerber, G.; Derory, A.; Sereni, J.G.; Kappler, J.P.
Title Magnetic and thermal properties of Ce2Pd2Sn Type Journal Article
Year 2008 Publication (up) Journal of Magnetism and Magnetic Materials Abbreviated Journal J. Magn. Magn. Mater.
Volume 320 Issue 6 Pages 1141-1145
Keywords
Abstract X-ray diffraction, susceptibility and specific heat studies on ternary Ce2Pd2Sn intermetallic compound and on its isostructural nonmagnetic compound La2Pd2Sn are reported. On Ce2Pd2Sn in absence of magnetic field, we confirm the existence of two magnetic transitions at T-N = 4.8K (antiferromagnetic transition) and T-C = 2.2K (ferromagnetic transition) and the specific heat results, measured down to 0.5 K, allow to recognize the transition at 2.2K as a first-order transition. A description based on molecular field calculations for the S = 1/2 resonant level model leads to a characteristic Kondo T-K of about 3K. (C) 2007 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:000254416300060 Approved no
Call Number BT @ hernan @ Serial 49
Permanent link to this record
 

 
Author Sereni, J.G.; Caroca-Canales, N.; Geibel, C.
Title Ferromagnetic instability at the edge of intermediate valence Type Journal Article
Year 2007 Publication (up) JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Abbreviated Journal
Volume 310 Issue 2 Pages E214-E216
Keywords
Abstract Preliminary study of structural, thermal and magnetic properties on ferromagnetic CePt1-yRhy (0.40 <= y <= 1) is presented. Like in the recently studied CePd1-xRhx, this new system undergoes a quantum critical behavior between the ferromagnetic CePt (T-C = 6K) and unstable valence CeRh. Regardless the electronic and atomic size similarities between Pt and Pd atoms, signi. cant differences in their respective phase diagrams are observed around the critical points. While CePd1-xRhx shows an asymptopic T-C(x) decrease indicating a smeared quantum phase transition, in CePt1-yRhyTC(y) vanishes beyond y = 0.80 after a plateau starting at y = 0.60 at T-C approximate to 1.8K. Peculiarities of this critical region are compared with other Ce-systems. (c) 2006 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:000247666000326 Approved no
Call Number BT @ hernan @ Serial 51
Permanent link to this record
 

 
Author Tovar, M.; Sereni, J.G.; Pedrazzini, P.; Caneiro, A.; Prado, F.; Butera, A.; Causa, M.T.
Title Magnetization and specific heat of La doped Sr2FeMoO6 Type Journal Article
Year 2004 Publication (up) JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Abbreviated Journal J. Magn. Magn. Mater.
Volume 272 Issue Pages 857-858
Keywords
Abstract We present high-temperature magnetization and low-temperature specific heat measurements performed on the electron doped double perovskite Sr1.7La0.3FeMoO6. We have obtained the electronic contribution to C-p, gamma = 11.5(5) mJ/mol K-2. The electronic susceptibility, derived from the magnetic measurements in the paramagnetic regime (T > T-c = 390K), was chi(e)(0) =(4.9 +/- 1.5) x 10(-4) emu/mol. Anti ferromagnetic coupling between localized and itinerant moments was inferred from the data, with a coupling constant lambda = -(475 +/- 50)mol/emu, that results in a ferromagnetic-like Curie-Weiss susceptibility with Theta = 390(5) K. These results are compared with those obtained for the undoped material. (C) 2003 Published by Elsevier B.V.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:000222236700045 Approved no
Call Number BT @ hernan @ Serial 63
Permanent link to this record
 

 
Author Vildosola, V.L.; Llois, A.M.; Weissmann, M.; Sereni, J.G.
Title Magnetic behaviour of Ce(Pd1-xMx) compounds (M = Rh, Ni and Ag) within the LDA approximation Type Journal Article
Year 2001 Publication (up) Journal of Magnetism and Magnetic Materials Abbreviated Journal J. Magn. Magn. Mater.
Volume 236 Issue 1-2 Pages 6-8
Keywords
Abstract Ce intermetallic compounds have been intensively studied in the last few decades due to the large variety of behaviours they exhibit. In particular, two ways of demagnetizing Ce have been experimentally tried within the ferromagnetic systems Ce(Pd1-xMx), namely through electronic concentration variations (M=Rh) and volume reductions (M=Ni). On the other hand, when Pd is substituted by Ag, a transformation from a ferromagnetic to an antiferromagnetic ground state has been observed. In this work, we analyse the evolution of the magnetism of Ce in the above-mentioned family of compounds by calculating the spin contribution to magnetism that results from spin polarised LDA calculations. (C) 2001 Elsevier Science B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:000171670100004 Approved no
Call Number BT @ hernan @ Serial 75
Permanent link to this record
 

 
Author SERENI, J.G.; TROVARELLI, O.
Title CORRELATION BETWEEN THE HYBRIDIZATION STRENGTH AND THE CE TO CE-LIGAND SPACING IN CET(2)X(2) COMPOUNDS Type Journal Article
Year 1995 Publication (up) JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Abbreviated Journal
Volume 140 Issue Pages 885-886
Keywords
Abstract The hybridization strength of the Ce-4f electrons with d or p orbitals of neighbouring sites, is analyzed through the comparison of the Ce-T and Ce-X spacings in CeT(2)X(2) compounds. Four different regimes, directly related to the increase of the hybridization strength, are recognized. This systematic indicates that the Ce behaviour depends more strongly on the overlap of f-p than of f-d orbitals.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:A1995QM07400073 Approved no
Call Number BT @ hernan @ Serial 100
Permanent link to this record
 

 
Author TROVARELLI, O.; SERENI, J.G.; SCHMERBER, G.; KAPPLER, J.P.
Title COEXISTENCE OF KONDO AND SPIN-GLASS BEHAVIOR IN CE4Y3NI3 Type Journal Article
Year 1995 Publication (up) JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Abbreviated Journal
Volume 140 Issue Pages 1211-1212
Keywords
Abstract Magnetic susceptibility chi and specific heat C-p measurements on Ce4Y3Ni3 are presented. The temperature of the maximum of chi(ac)(T) and C-p(T) shifts with frequency and applied field respectively, as expected for a spin glass (SG) system. The C-p (T --> 0) dependence corresponds to that of an anisotropic SG. According to the entropy gain two Ce atoms are involved in the SG contribution and two exhibit Kondo effect.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:A1995QM07400233 Approved no
Call Number BT @ hernan @ Serial 101
Permanent link to this record
 

 
Author Kappler, J.P.; Schmerber, G.; Sereni, J.G.
Title Magnetic and thermal properties of Ce5Rh3 Type Journal Article
Year 1992 Publication (up) Journal of Magnetism and Magnetic Materials Abbreviated Journal J. Magn. Magn. Mater.
Volume 115 Issue 2-3 Pages 241-244
Keywords
Abstract Magnetic susceptibility, high field magnetization and specific heat measurements on Ce5Rh3 are reported. Two antiferromagnetic transitions are observed at T(N)=4.5 K and T(N)'=2.6 K. The magnetization curve at 1.5 K reveals a nontrivial magnetic structure in this compound, with a saturation magnetization of 0.72mu(B). The high temperature Curie constant (0.64 emu K/mol), the Curie-Weiss constant (THETA(p)=-45 K) and the entropy related with the magnetic transitions (DELTAS(m)=0.8 R In 2) indicate the presence of a Kondo-type component in the ground state of Ce5Rh3.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:A1992JV02200022 Approved no
Call Number BT @ hernan @ Serial 111
Permanent link to this record
 

 
Author Sereni, J.G.; Kappler, J.P.
Title Magnetic and thermal properties of CeCu Type Journal Article
Year 1992 Publication (up) Journal of Magnetism and Magnetic Materials Abbreviated Journal J. Magn. Magn. Mater.
Volume 109 Issue 2-3 Pages 349-352
Keywords
Abstract Magnetic susceptibility, high field magnetization and specific heat measurements on CeCu are presented. An antiferromagnetic transition is observed at T(N) = 313 K, with some evidences of low dimensionality of the order parameter. The saturation magnetization. M(s) = 1.16-mu(B), implies that the crystalline electric field (CEF) ground state doublet is strongly magnetic, in agreement with the low temperature Curie constant C = 0.46 emu K/mol. In the high temperature limit (T > 50 K), the obtained Curie constant is C = 0.65 emu K/mol, which suggests an overall CEF splitting larger than 200 K. The entropy gain at the magnetic transition is 72% of the expected R in 2. The missing entropy is related to a specific heat anomaly with a maximum at approximately 13 K, which is attributed to magnetic fluctuations in the Ce chains. The transition temperature and the high temperature broad maximum in the specific heat are weakly affected by an applied magnetic field of 1 T.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:A1992HP06000034 Approved no
Call Number BT @ hernan @ Serial 112
Permanent link to this record
 

 
Author 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 (up) Journal of Magnetism and Magnetic Materials Abbreviated Journal J. Magn. Magn. Mater.
Volume 108 Issue 1-3 Pages 183-184
Keywords
Abstract 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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:A1992HH32900075 Approved no
Call Number BT @ hernan @ Serial 113
Permanent link to this record
 

 
Author 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 (up) JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Abbreviated Journal
Volume 108 Issue 1-3 Pages 185-186
Keywords
Abstract 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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:A1992HH32900076 Approved no
Call Number BT @ hernan @ Serial 114
Permanent link to this record