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Author Sereni, J.G.
Title (up) Comparative study of magnetic phase diagrams of Ce compounds Type Journal Article
Year 1998 Publication Journal of the Physical Society of Japan Abbreviated Journal J. Phys. Soc. Japan
Volume 67 Issue 5 Pages 1767-1775
Keywords
Abstract Thermal properties of magnetically ordered Ce-lattice systems are compared in their crossover to the non-magnetic state, driven by alloying effects. The ordering temperature (T-ord=T-N or T-C) is found to go to zero continuously only in a few cases, while in others a discontinuity in its decrease is clearly observed. Coincidentally, the magnetic contribution to the specific heat (C-p), the entropy and the free energy variations with temperature mark an evident difference between those cases. Furthermore, the extension of the non-fermi-liquid (NFL) phase in terms of concentration variation correlates with differences observed in the respective ordered phase. A systematic transformation from a mean field like transition to a fluctuation dominated type is observed in C-p(T), as the system overcomes a characteristic crossover concentration. Such a concentration appears as a limit for the NFL behavior in the paramagnetic phase above T-ord. A possible origin of the mentioned differences are discussed in terms of some alternatives in the evolution of the magnetic moments and the strength of their interactions.
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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 0031-9015 ISBN Medium
Area Expedition Conference
Notes ISI:000073878900044 Approved no
Call Number BT @ hernan @ Serial 87
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Author Bauer, E.; Kaldarar, H.; Prokofiev, A.; Royanian, E.; Amato, A.; Sereni, J.G.; Bramer-Escamilla, W.; Bonalde, I.
Title (up) Heavy Fermion Superconductivity and Antiferromagnetic Ordering in CePt3Si without Inversion Symmetry Type Journal Article
Year 2007 Publication Journal of the Physical Society of Japan Abbreviated Journal J. Phys. Soc. Japan
Volume 76 Issue 5 Pages 051009
Keywords
Abstract Heavy fermion superconductivity in absence of inversion symmetry of the crystal structure is basically controlled by a Rashba-like antisymmetric spin orbit coupling which splits the Fermi surface and removes the spin degeneracy of electrons. The Fermi surface splitting originates a mixing of spin-singlet and spin-triplet states in the superconducting condensate. Such constraints are responsible for various uncommon features of the superconducting ground state and are discussed here in view of CePt 3 Si, the first heavy fermion superconductor missing a centre of symmetry. We recall and discuss normal and superconducting properties of CePt 3 Si and relate them to recently developed phenomenological theories.
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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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 687
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Author Sereni, J.G.
Title (up) Thermodynamical analysis of the magnetic phase diagrams of Ce systems Type Journal Article
Year 2001 Publication Journal of the Physical Society of Japan Abbreviated Journal J. Phys. Soc. Japan
Volume 70 Issue 7 Pages 2139-2150
Keywords
Abstract Three types of magnetic phase diagrams as a function of composition or pressure, f (z, p), are identified among Ce systems: I) with the ordering temperature T-ord --> 0 monotonously, followed by a narrow region where non-Fermi-liquid (NFL) behavior is observed; II) with T-ord vanishing at finite temperature, but followed by an extended NFL region, and III) where T-ord remains nearly constant. Among the analyzed systems intrinsic differences are found in the evolution of their respective properties, namely: in group-1 an increase of the density of excitations is observed below T-ord. In group-II the evanescense of T-ord(z, p) coincides with the extrapolation to zero of the magnetic free energy (DeltaG --> 0), and the existence of a reference function implying that T-K not equal f (z, p), whereas T-ord = f (z, p). Finally, group-III is also characterized by the evanescense of T-ord where DeltaG --> 0, but in this case T-ord not equal f (z, p) whereas T-K = f (z, p). The characteristics of each group are discussed and compared together with the different C-p(T)/T dependencies at T greater than or equal to T-ord and some related scalings, which allow to recognize a quasi-paramagnetic phase.
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 0031-9015 ISBN Medium
Area Expedition Conference
Notes ISI:000170077600046 Approved no
Call Number BT @ hernan @ Serial 77
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