| Records |
| 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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| Abstract |
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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BT @ gnieva @ |
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425 |
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Franco, D.G.; Carbonio, R.E.; Kaul, E.E.; Nieva, G. |
| Title |
Tailoring the ground state of the ferrimagnet La2Ni(Ni1/3Sb2/3)O6 |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
346 |
Issue |
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Pages |
196-202 |
| Keywords |
Ferrimagnetic; Double perovskite; Magnetic frustration; Superexchange and super-superexchange interaction; Magnetic oxide |
| Abstract |
We report on the magnetic and structural properties of La2Ni(Ni1/3Sb2/3)O6 in polycrystal, single crystal and thin film samples. We found that this material is a ferrimagnet ( T c ≈ 100 K ) which possesses a very distinctive and uncommon feature in its virgin curve of the hysteresis loops. We observe that bellow 20 K it lies outside the hysteresis cycle, and this feature was found to be an indication of a microscopically irreversible process possibly involving the interplay of competing antiferromagnetic interactions that hinder the initial movement of domain walls. This initial magnetic state is overcome by applying a temperature dependent characteristic field. Above this field, an isothermal magnetic demagnetization of the samples yield a ground state different from the initial thermally demagnetized one. |
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0304-8853 |
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BT @ pedrazp @ |
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666 |
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Betancourth, D.; Facio, J.I.; Pedrazzini, P.; Jesus, C.B.R.; Pagliuso, P.G.; Vildosola, V.; Cornaglia, P.S.; García, D. J.; Correa, V. F. |
| Title |
Low Temperature magnetic properties of GdCoIn5 |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
374 |
Issue |
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Pages |
744-747 |
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A comprehensive experimental and theoretical study of the low temperature properties of GdCoIn5 was performed. Specific heat, thermal expansion, magnetization and electrical resistivity were measured in good quality single crystals down to 4He temperatures. All the experiments show a second-order-like phase transition at 30 K probably associated with the onset of antiferromagnetic order. The magnetic susceptibility shows a pronounced anisotropy below T N with an easy magnetic axis perpendicular to the crystallographic ĉ-axis. Total energy GGA+U calculations indicate a ground state with magnetic moments localized at the Gd ions and allowed a determination of the Gd-Gd magnetic interactions. Band structure calculations of the electron and phonon contributions to the specific heat together with Quantum Monte Carlo calculations of the magnetic contributions show a very good agreement with the experimental data. Comparison between experiment and calculations suggests a significant anharmonic contribution to the specific heat at high temperature (View the MathML sourceT≳100K). |
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BT @ victor.correa @ |
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701 |
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Facio, J.I.; Betancourth, D.; Cejas Bolecek, N.R.; Jorge, G.A.; Pedrazzini, P.; Correa, V.F.; Cornaglia, P.S.; Vildosola, V.; García D.J. |
| Title |
Lattice specific heat for the RMIn5 (R=Gd, La,Y; M=Co, Rh) compounds: Non-magnetic contribution subtraction |
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Journal Article |
| Year |
2016 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
407 |
Issue |
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Pages |
406-4011 |
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BT @ victor.correa @ |
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730 |
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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 @ |
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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 |
Type |
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 @ |
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63 |
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Braghta, A.; Schmerber, G.; Derory, A.; Sereni, J.G.; Kappler, J.P. |
| Title |
Magnetic and thermal properties of Ce2Pd2Sn |
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Journal Article |
| Year |
2008 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
| Volume |
320 |
Issue |
6 |
Pages |
1141-1145 |
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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. |
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0304-8853 |
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ISI:000254416300060 |
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no |
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BT @ hernan @ |
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49 |
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SERENI, J.G. |
| Title |
The role of “p-like†orbitals in Ce valence instabilities |
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Journal Article |
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1985 |
Publication |
Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
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47-48 |
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FEB |
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228-230 |
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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 |
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BT @ hernan @ |
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131 |
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Sereni, J.G.; Nieva, G.; Kappler, J.P. |
| Title |
ANOMALOUS CRYSTAL-FIELD EFFECTS IN THE SPECIFIC-HEAT OF CE-HEAVY FERMION COMPOUNDS |
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Journal Article |
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1987 |
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Journal of Magnetism and Magnetic Materials |
Abbreviated Journal |
J. Magn. Magn. Mater. |
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63-64 |
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101-103 |
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0304-8853 |
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ISI:A1987G356900031 |
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BT @ hernan @ |
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128 |
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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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BT @ hernan @ |
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129 |
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