| Records |
| Author |
Sereni, J.G.; Kappler, J.P. |
| Title |
Magnetic and thermal properties of CeCu |
Type |
Journal Article |
| Year |
1992 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
Volume  |
109 |
Issue |
2-3 |
Pages |
349-352 |
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| 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. |
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0304-8853 |
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ISI:A1992HP06000034 |
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BT @ hernan @ |
Serial |
112 |
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| Author |
Kappler, J.P.; Schmerber, G.; Sereni, J.G. |
| Title |
Magnetic and thermal properties of Ce5Rh3 |
Type |
Journal Article |
| Year |
1992 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
115 |
Issue |
2-3 |
Pages |
241-244 |
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| 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. |
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0304-8853 |
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ISI:A1992JV02200022 |
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no |
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BT @ hernan @ |
Serial |
111 |
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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 |
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS |
Abbreviated Journal |
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140 |
Issue |
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Pages |
885-886 |
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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. |
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0304-8853 |
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ISI:A1995QM07400073 |
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BT @ hernan @ |
Serial |
100 |
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TROVARELLI, O.; SERENI, J.G.; SCHMERBER, G.; KAPPLER, J.P. |
| Title |
COEXISTENCE OF KONDO AND SPIN-GLASS BEHAVIOR IN CE4Y3NI3 |
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Journal Article |
| Year |
1995 |
Publication |
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS |
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140 |
Issue |
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Pages |
1211-1212 |
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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. |
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0304-8853 |
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| Notes |
ISI:A1995QM07400233 |
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no |
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BT @ hernan @ |
Serial |
101 |
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| Author |
Steren, L.B.; Sirena, M.; Guimpel, J. |
| Title |
Substrate influence on the magnetoresistance and magnetic order in La0.6Sr0.4MnO3 films |
Type |
Journal Article |
| Year |
2000 |
Publication |
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS |
Abbreviated Journal |
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| Volume |
211 |
Issue |
1-3 |
Pages |
28-34 |
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We report structural, magnetic and transport measurements on La0.6Sr0.4MnO3 thin films grown on MgO and TiSrO3 substrates with thickness varying from 5 to 500 nm. We find that the lattice mismatch between substrates and films affects the morphology and induced-strains of the films. We show that these two different effects strongly influence the ferromagnetic order, the metal-insulator transition, the localization of the current carriers and the magnetoresistance of these materials. (C) 2000 Elsevier Science B.V. All rights reserved. |
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0304-8853 |
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| Notes |
ISI:000085772100006 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
179 |
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| Author |
Sirena, M.; Steren, L.B.; Guimpel, J. |
| Title |
Magnetic after-effect in manganite films |
Type |
Journal Article |
| Year |
2001 |
Publication |
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS |
Abbreviated Journal |
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| Volume |
226 |
Issue |
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Pages |
847-848 |
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The time dependence of the magnetic and transport properties on La0.6Sr0.4MnO3 films and bulk samples has been studied through magnetization and resistivity measurements. A magnetic after-effect has been observed in all samples. At low temperatures, the low-field magnetization, can be described by the function M(t) = M-c + M-d exp(-t/tau) + S(H, T)ln(t), The resistivity increases logarithmically in the same temperature range. indicating the evolution of the sample to a more disordered state. Above a characteristic temperature, this behaviour is reversed and an increase of the magnetization with time is observed. The relaxation parameters depend on the bulk or films character of the samples. In the latter case, a dependence on the film thickness was found. A direct correlation between the time dependence of the resistivity and magnetization curves in manganite compounds was found. (C) 2001 Elsevier Science B.V. All rights reserved. |
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0304-8853 |
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ISI:000170708600308 |
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no |
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BT @ hernan @ |
Serial |
174 |
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Pedrazzini, P.; Berisso, M.G.; Sereni, J.G.; Trovarelli, O.; Geibel, C. |
| Title |
Magnetic phase diagram of Ce(CuxRh1-x)(2) Si-2 |
Type |
Journal Article |
| Year |
2001 |
Publication |
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS |
Abbreviated Journal |
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226 |
Issue |
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Pages |
161-163 |
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Magnetic, thermal and transport measurements on Ce(CuxRh1-x)(2)Si-2 are presented, The obtained phase diagram shows a rapid decrease of the magnetic order on the Rh rich-side. as determined by magnetic susceptibility measurements, followed by a region without magnetic order for x > 0.2. In this region, the electronic specific heat coefficient increases moderately up to 0.2J/mol K-2 for x = 0.8. evaluated at 0.5 K. Around 5 K a small anomaly is observed in the 0.8. As a function of doping, a maximum develops below 10 K in the electrical resistance. specific heat for 0.4 less than or equal to x less than or equal to 0.8. As a function of doping, a maximum develops below 10 K in the electru=ical resistance. Particularly, at x = 0.8, the temperature of the maximum of the electrical resistance slope coincides with the anomaly observed in the specific heat. (C) 2001 Elsevier Science B.V. All rights reserved. |
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0304-8853 |
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| Notes |
ISI:000170708600054 |
Approved |
no |
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BT @ hernan @ |
Serial |
297 |
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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 |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
236 |
Issue |
1-2 |
Pages |
6-8 |
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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. |
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0304-8853 |
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ISI:000171670100004 |
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no |
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BT @ hernan @ |
Serial |
75 |
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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 |
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Journal Article |
| Year |
2004 |
Publication |
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
272 |
Issue |
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Pages |
857-858 |
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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. |
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0304-8853 |
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ISI:000222236700045 |
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BT @ hernan @ |
Serial |
63 |
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Sirena, M.; Haberkorn, N.; Granada, M.; Steren, L.B.; Guimpel, J. |
| Title |
Oxygen and disorder effect in the magnetic properties of manganite films |
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Journal Article |
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2004 |
Publication |
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS |
Abbreviated Journal |
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272 |
Issue |
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Pages |
1171-1173 |
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We have made a systematic study of the magnetic properties of low doped manganite films submitted to different oxygenation treatments. We have found that oxygenation dynamics depends critically of the strain field in the sample. The T-C and the Mr increase as the oxygen content is increased. A decrease of the coercive field of the LSMO-STO films was observed, indicating that annealing treatments increase the oxygen content reducing oxygen vacancies. (C) 2004 Elsevier B.V. All rights reserved. |
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0304-8853 |
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ISI:000222236700179 |
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BT @ hernan @ |
Serial |
162 |
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