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Author Trovarelli, O.; Gomez-Berisso, M.; Pedrazzini, P.; Bosse, D.; Geibel, C.; Sereni, J.G.; Steglich, F.
Title Metallurgic, structural and magnetic properties of Ce(Pd1-rRhr)(2)Si-2 Type Journal Article
Year (up) 1998 Publication JOURNAL OF ALLOYS AND COMPOUNDS Abbreviated Journal
Volume 275 Issue Pages 569-573
Keywords
Abstract We report on investigations of the metallurgic, crystallographic and magnetic properties of the Ce(Pd1-rRhr)(2)Si-2 system. While the as-cast samples show a miscibility gap for 0.3<r<0.7, complete miscibility with a monotonous evolution of the lattice parameters is found in samples annealed at 1200 degrees C. Although both pure compounds order antiferromagnetically at 10 K (r=0) and 36 K (r=1) respectively, our magnetic susceptibility (chi) results indicate a magnetically non-ordered state at intermediate concentrations. The ordering temperature decreases smoothly and continuously on the Pd-rich side, vanishing between r=0.2 and r=0.3. On the Rh-rich side, this decrease is faster and at r=0.8 the long-range magnetic order is replaced by enhanced magnetic fluctuations as evidenced by a broad maximum in chi(T) around 25 K. The orientation-dependent chi of the strongly textured samples indicates an evolution towards an easy-axis system with increasing Rh content. The results are discussed and compared to the related systems Ce(Pd1-xTx)(2)Si-2 (T=Ru and Cu). (C) 1998 Elsevier Science S.A.
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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 0925-8388 ISBN Medium
Area Expedition Conference
Notes ISI:000075617700123 Approved no
Call Number BT @ hernan @ Serial 85
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Author Berisso, M.G.; Trovarelli, O.; Pedrazzini, P.; Zwicknagl, G.; Geibel, C.; Steglich, F.; Sereni, J.G.
Title Nonmonotonous evolution of the Kondo temperature in the phase diagram of Ce(Pd1-xCux)(2)Si-2 Type Journal Article
Year (up) 1998 Publication Physical Review B – Condensed Matter and Materials Physics Abbreviated Journal Phys. Rev. B
Volume 58 Issue 1 Pages 314-321
Keywords
Abstract The evolution of the behavior of the Ce 4f electron with the Cu content in the alloy Ce(Pd1-xCux)(2)Si-2 was investigated by determining its structural, magnetic, transport, and thermal properties. Results obtained on 15 samples with compositions distributed along the whole concentration range allow us to draw a magnetic phase diagram showing three distinct regions. The first region at low Cu concentrations corresponds to the antiferromagnetic-ordered regime. The fast suppression of this magnetic order between x = 0.2 and x = 0.25 suggests the presence of a critical point which separates this region from the second one at larger.x values where no magnetic order is observed. The main characteristic of this second region, which extends up to x = 0.7, is a pronounced increase of the Kondo temperature T-K, from T-K approximate to 15 K at x = 0.25 to T-K approximate to 50 K at x = 0.7. This is in contrast with the fast decrease of T-K in the region with x > 0.7. In this region a small anomaly with a ferromagnetic character is observed in the specific hear arround 4 K. The change in the evolution of T-K with x coincides with a change in the composition dependence of the c lattice parameter of the tetragonal structure, pointing to a structure-related origin of this unusual T-K(x) behavior. This nonmonotonous T-K(x) dependence is reproduced using local-density-approximation band-structure calculations, which show a maximum of the hybridization strength between conduction electrons and Ce 4f stares for intermediate Cu concentrations. Such a T-K(x) dependence which contradicts the monotonous dependence observed in all other Ce-based alloy systems is the hallmark of the Ce(Pd1-xCux)(2)Si-2 alloy, which cannot be described as a Fermi-Liquid system in the nonmagnetic region. [S0163-1829(98)02118-3].
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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 0163-1829 ISBN Medium
Area Expedition Conference
Notes ISI:000074643200061 Approved no
Call Number BT @ hernan @ Serial 302
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Author Gomez-Berisso, M.; Pedrazzini, P.; Sereni, J.G.; Trovarelli, O.; Geibel, C.; Steglich, F.
Title Low-temperature properties of the Ce(Pd1-rRhr)(2)Si-2 system Type Journal Article
Year (up) 1999 Publication PHYSICA B Abbreviated Journal
Volume 258-261 Issue Pages 68-69
Keywords
Abstract The ground state of the Ce(Pd1-rRhr)(2)Si-2 system is studied by means of magnetic susceptibility and low-temperature specific heat measurements (Cp) throughout the concentration range. The antiferromagnetic order of both stoichiometric extremes (T-N = 10.3 and 36 K for r = 0 and 1, respectively) drops abruptly below 0.4 K with mon than 30% of Pd substitution by Rh and 20% of Rh substitution by Pd on the respective sides. No magnetic order is observed between those concentrations, where the low-temperature behaviour is characterized by a C-P(T --> 0)/T divergency that continuously decreases (like the asociated entropy gain) as the Ph concentration increases. (C) 1999 Elsevier Science B.V. All rights reserved.
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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 0921-4526 ISBN Medium
Area Expedition Conference
Notes ISI:000079315700030 Approved no
Call Number BT @ hernan @ Serial 80
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Author Bauer, E.; Hauser, R.; Galatanu, A.; Michor, H.; Hilscher, G.; Sereni, J.; Berisso, M.G.; Pedrazzini, P.; Galli, M.; Marabelli, F.; Bonville, P.
Title Non-Fermi-liquid behavior of YbCu5-xAlx Type Journal Article
Year (up) 1999 Publication Physical Review B Abbreviated Journal Phys. Rev. B
Volume 60 Issue 2 Pages 1238-1246
Keywords
Abstract A valency change in YbCu5-xAlx from nu approximate to 2.2(x=0) to nu=3(x=2) causes a magnetic instability near a critical concentration x(cr)approximate to 1.5 Alloys in the vicinity of x(cr) exhibit typical non-Fermi-liquid properties like a negative logarithmic contribution to the specific heat or substantial deviations of the electrical resistivity from a T-2 behavior. Both pressure and alloying in this series bring about a strong reduction of the Kondo temperature T-K; the crystal-held interaction and the interatomic exchange gain therefore importance and magnetic order becomes possible beyond x(cr).
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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 0163-1829 ISBN Medium
Area Expedition Conference
Notes ISI:000081563800070 Approved no
Call Number BT @ hernan @ Serial 301
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Author Pedrazzini, P.; Schmerber, G.; Berisso, M.G.; Kappler, J.P.; Sereni, J.G.
Title Magnetic and superconducting properties of A(7)B(3) compounds (A = Th or La and B=Ni, Co, Fe or Pd, Rh, Ru) Type Journal Article
Year (up) 2000 Publication PHYSICA C Abbreviated Journal
Volume 336 Issue 1-2 Pages 10-18
Keywords
Abstract High-temperature magnetization, low temperature specific heat, and ac-susceptibility measurements on Th7X3 (X = Ni, Co, and Fe) and La(7)Z(3) (Z = Pd, Rh, and Ru) superconductors are presented. The magnetic behaviour of the Th7X3 group has the characteristics of Pauli paramagnets. The La(7)Z(3) group also shows Pauli paramagnetism for Z = Pd and Ru, and signs of spin fluctuations for La7Rh3. Specific heat (C-p) measurements indicate a conventional BCS behaviour for La7Pd3 and La7Rh3, like that of the previously measured Th7X3 superconductors. in the case of La7Ru3, the reduced specific heat jump at the transition, the anomalous temperature dependence of C-p under magnetic field and a large upper critical field slope are discussed. (C) 2000 Elsevier Science B.V. All rights reserved.
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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 0921-4534 ISBN Medium
Area Expedition Conference
Notes ISI:000088047500002 Approved no
Call Number BT @ hernan @ Serial 78
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Author Berger, S.; Galatanu, A.; Hilscher, G.; Michor, H.; Paul, C.; Bauer, E.; Rogl, P.; Gomez-Berisso, M.; Pedrazzini, P.; Sereni, J.G.; Kappler, J.P.; Rogalev, A.; Matar, S.; Weill, F.; Chevalier, B.; Etourneau, J.
Title Experimental study of physical properties in the complex magnetic phase diagram of Ce(Rh1-xRux)(3)B-2 Type Journal Article
Year (up) 2001 Publication Physical Review B Abbreviated Journal Phys. Rev. B
Volume 64 Issue 13 Pages 134404
Keywords
Abstract We report on a series of structural, magnetic, and thermodynamic measurements, a study of transport properties and x-ray absorption edge spectroscopy on Ce(Rh1-xRux)(3)B-2. These investigations evidence that in addition to the already established ferromagnetic range for x less than or equal to0.06, a complex antiferromagnetic structure exists for concentrations 0.1 less than or equal tox less than or equal to0.35. The behavior in the latter regime is dominated by an extraordinary strong intersite coupling; however, the magnetic moments involved appear to be very small. At the phase boundary to the paramagnetic regime (x approximate to0.4), significant deviations from a Fermi-liquid behavior occur.
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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 0163-1829 ISBN Medium
Area Expedition Conference
Notes ISI:000171426700059 Approved no
Call Number BT @ hernan @ Serial 74
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Author 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 (up) 2001 Publication JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Abbreviated Journal
Volume 226 Issue Pages 161-163
Keywords
Abstract 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.
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:000170708600054 Approved no
Call Number BT @ hernan @ Serial 297
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Author Berisso, M.G.; Pedrazzini, P.; Sereni, J.G.; Trovarelli, O.; Geibel, C.; Steglich, F.
Title Study of Ce(Rh1-xPdx)(2)Si-2: pronounced differences between the CeRh2Si2 and CePd2Si2 ground states Type Journal Article
Year (up) 2002 Publication EUROPEAN PHYSICAL JOURNAL B Abbreviated Journal
Volume 30 Issue 3 Pages 343-349
Keywords
Abstract We present electrical resistivity and specific heat measurements of alloys on the Rh rich side of the phase diagram of the Ce(Rh1-xPdx)(2)Si-2 system. We compare these results with those obtained at intermediate and low Rh concentrations. The analysis of the concentration and temperature dependence of the entropy and of the scaling behaviour of C-et(T) and rho(T) clearly confirm a separation of the magnetic phase diagram into two regions: the region x less than or equal to 0.3, showing a concentration independent characteristic temperature for the 4f-electrons with T-0 approximate to 45 K, while for x > 0.3, T-0 decreases to T-0(x = 1) approximate to 15 K. At low Pd-content, T-N decreases very rapidly from T-N = 36 K in pure CeRh2Si2 to T-N = 18 K at x = 0.1. With higher Pd concentration T-N stabilizes at T-N approximate to 15 K whereas the magnitude of the anomalies in C-et(T) and in the susceptibility around T-N are further reduced and disappear at x approximate to 0.3. This differs from the behavior found on the Pd-rich side, where T-N decreases continuously to zero with increasing Rh content. The pronounced differences observed between both phase boundaries and the drastic effect of doping on the Rh rich side suggest an itinerant character in CeRh2 Si-2, in contrast with the localized character of CePd2Si2. Further evidence for the itinerant character of CeRh2Si2 is given by the rho(T) dependence observed for x less than or equal to 0.3, which scales with rho(T) of the prototype itinerant compound YCo2.
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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 1434-6028 ISBN Medium
Area Expedition Conference
Notes ISI:000180850100009 Approved no
Call Number BT @ hernan @ Serial 69
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Author Pedrazzini, P.; Berisso, M.G.; Caroca-Canales, N.; Deppe, M.; Geibel, C.; Sereni, J.G.
Title Non-Fermi liquid behaviour in cubic CeIn3-xSnx Type Journal Article
Year (up) 2002 Publication PHYSICA B-CONDENSED MATTER Abbreviated Journal
Volume 312 Issue Pages 406-407
Keywords
Abstract The alloy between the antiferromagnetic (AF) CeIn3 and the mixed valent CeSn3 is particularly interesting since it is one of the few cases where a magnetic to non-magnetic transition is observed in a cubic system. Although the resulting alloy CeIn3-xSnx has been investigated for over 20 years, no information is available about thermodynamic and transport properties below 2K. We report first measurements on resistivity rho(T) and specific heat C-P(T) down to 0.45 K. These results confirm the disappearance of the AF state near xcongruent to0.6. In samples close to this critical concentration, we observe a strong departure from the Fermi liquid behaviour, i.e. rho(T) approximate to rho(0) + a T-n (n < 1.5) and a logarithmic temperature dependence C-P(T)infinity – T ln (T), in more than a decade above the lowest investigated temperature. (C) 2002 Elsevier Science B.V. All rights reserved.
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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 0921-4526 ISBN Medium
Area Expedition Conference
Notes ISI:000175871000148 Approved no
Call Number BT @ hernan @ Serial 72
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Author Berisso, M.G.; Pedrazzini, P.; Deppe, M.; Trovarelli, O.; Geibel, C.; Sereni, J.G.
Title Composition dependence of the magnetic properties of Ge-doped CeCu2Si2 Type Journal Article
Year (up) 2002 Publication PHYSICA B-CONDENSED MATTER Abbreviated Journal
Volume 320 Issue 1-4 Pages 380-383
Keywords
Abstract Due to the proximity of CeCu2Si2 to a quantum critical point, the ground state of this compound is extremely sensitive to sample preparation conditions. Small excess of one component can lead to magnetic or superconducting behaviors. We found that in the alloy CeCu2(Si1-xGex)(2) a small excess of Ge enhances the homogeneity range allowing a precise investigation of stoichiometric effects on the physical properties. In this system, Ge doping produces an increment of the antiferromagnetic transition temperature T-N, while the superconducting one decreases. Particularly, it was found that at x = 0.1 both phases coexist at low temperature. In order to investigate the stability of these phases against changes of the Ce-ligands composition, we prepared a series of CeCu2+y(Si0.9Ge0.1)2-x, samples (0less than or equal toyless than or equal to0.10) and investigated their specific heat and electrical resistivity. We observed that the substitution of Si/Ge by Cu increases the characteristic temperature and weakens the magnetic contribution without modifying TN. A further transition, of the first order character, is observed at lower temperature. (C) 2002 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 0921-4526 ISBN Medium
Area Expedition Conference
Notes ISI:000177607700103 Approved no
Call Number BT @ hernan @ Serial 294
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