Download Free Cerium Heavy Fermion Compounds Near Their T Book in PDF and EPUB Free Download. You can read online Cerium Heavy Fermion Compounds Near Their T and write the review.

Measurements of the temperature-dependent specific heat and thermal expansion coefficient near a T = 0 magnetic-non-magnetic boundary, accessed in CeRh2Si2 by application of pressure and in CeRh{sub 2-x}Ru(subscript x)Si2 at ambient pressure by chemical substitution, emphasize the role of disorder in producing non-Fermi-liquid behavior. Interestingly, superconductivity also develops near this boundary in some crystallographically-ordered Ce-based heavy-fermion compounds.
We have re-examined the temperature-dependence of the valence band 4f features in Ce-based heavy fermions. We measured the phonon broadening of the Si-2p core levels in CeSi2 by determining the increase of the full width at half-maximum (FWHM) as a function of temperature. We discovered that all the temperature dependence is exactly accounted for, and there is none left over to attribute to any Kondo effects. We concluded that the feature of E{sub F} in Ce-based heavy fermions cannot be a Kondo resonance. 16 refs., 3 figs.
A theoretical investigation of many-body effects in Cerium and Uranium Heavy Fermion and Mixed Valent Compounds and their experimental manifestations in thermodynamic, transport, and spectroscopic properties is discussed in this report.
Heavy Fermion materials are a class of correlated electron materials that are best known for their partially filled 4-f and 5-f electron orbitals. These partially filled electron orbitals cause the formation of local magnetic moments within many of these materials which can lead to a vast array of interesting interaction with the conduction electrons. These interactions often manifest themselves as interesting physical phenomena, such as superconductivity, Fermi liquid/non-Fermi liquid behavior, magnetic ordering, and quantum criticality. In this work, we report on heat capacity measurements for a group of "1-2-20 cage compounds", and magnetoresistivity measurements for a samarium doped cerium based superconductor. Motivated to ascertain a better understanding of the electronic structure of these cage compounds, we first investigated multiple praseodymium and cerium based 1-2-20 cage compounds through heat capacity measurements down to 0.4 K and in magnetic fields up to 14 T. This analysis illuminated the ground state of the PrNi2Cd20 and PrPd2Cd20 materials to be non-Kramers doublet states, while for CeNi2Cd20 and CePd2Cd20, the ground state was a Kramers doublet. Further investigation into the cerium based compounds indicated that the lack of magnetic order normally seen in cerium based heavy fermions could potentially be attributed to this ground state driving a minimal Ruderman-Kasuya-Kittel-Yosida (RKKY) interaction strength in the material. We also analyzed samarium doped CeCoIn5, motivated to further explore the quantum critical behavior of this material and how it interacts with magnetism. Resistivity measurements in Ce1-xSmxCoIn5 display a clear onset of the Kondo effect within the material, evidenced by a local resistivity minimum. A closer inspection of the resistivity in this material shows that it can be expressed as a superposition of two portions, one positive and one negative. By separating the resistivity in this way, we can more closely examine the different physics at play, and how changes, such as doping concentration, effect the physical phenomena that occur. This analysis indicates that as the samarium concentration is increased, the material moves closer to the single impurity limit as Kondo coherence effects are lessened. Additionally, it can be seen through magnetoresistivity that this material exhibits two Kondo regimes, one conventional and one unconventional. We show that in the unconventional regime, the magnetic field required to break coherence effects increases, rather than decreases, potentially due to field quenching effects on spin fluctuations. Lastly, we examine the behavior of the field induced quantum critical point and its behavior as the samarium concentration changes. We found that as the samarium concentration increases, the field induced quantum critical point is rapidly suppressed, until it vanishes at a certain concentration. The same behavior can also be seen in the superconducting critical temperature, indicating that superconducting in this material could be mediated by anti-ferromagnetic (AFM) spin fluctuations.
During the Koln meeting (August 28-31, 1984), Irdia was chosen as the venue for the next International Conference on Valence Fluctuations. lhis was in recognition ard appreciation of the work done, both experimental ard theoretical, by the Irdian scientists in this area during the last decade. We decided to hold this Conference in the month of January, 1987 at Bangalore. lhe subject of Valence Fluctuations has kept itself alive ard active as it has provided many shocks ard suprises particularly among the Ce- ard U-based intermetallies. lhe richness of many interesting physical phenomena occurring in mixed valent materials, the flexibility of modifying their physical properties (by alloying, for example) ard the possibility of synthesizing a wide variety of new such materials seem to be the key factors in this regard. Barely six months before this Conference, an International Conference on Anomalous Rare Earths and Actinides (ICAREA) had been held at Grenoble (July, 1986) which also focussed on mixed valence ard heavy fermion phenomena. In spite of this, the response to this' Conference was very enthusiastic and encouraging. Many interesting ard important results were presented at this Conference which have been included in this volume.
The interplay of structural, orbital, charge, and spin degrees of freedom is at the heart of many emergent phenomena, including superconductivity. We find that unraveling the underlying forces of such novel phases is a great challenge because it not only requires understanding each of these degrees of freedom, it also involves accounting for the interplay between them. Cerium-based heavy fermion compounds are an ideal playground for investigating these interdependencies, and we present evidence for a correlation between orbital anisotropy and the ground states in a representative family of materials. We have measured the 4f crystal-electric field ground-state wave functions of the strongly correlated materials CeRh1xIrxIn5 with great accuracy using linear polarization-dependent soft X-ray absorption spectroscopy. These measurements show that these wave functions correlate with the ground-state properties of the substitution series, which covers long-range antiferromagnetic order, unconventional superconductivity, and coexistence of these two states.
The Hiroshima Workshop on Transport and Thermal Properties of f-Electron Systems, T2PfS, was held in the hotel Greenpia Yasuura on the shores of the Seto Inland Sea near Hiroshima, Japan from August 30, to September 2, 1992, as a satellite meeting of the International Conference of Strongly Correlated Electron Systems in Sendai. The purpose of this workshop was to bring together those scientists who are actively involved in the research of 4f- and 5f-electron systems; particularly the transport and thermal properties such as electrical resistivity, Hall effect, thermoelectric power, thermal conductivity, thermal expansion and specific heat. Hence, the organizing committee limited the number of participants to 60; 25 from abroad and 35 from Japan. In the workshop, all the sessions consisted of oral presentations; 25 invited talks and 5 contributed talks, including at least 10 minutes of discussion for each presentation. The program was divided into the following five topics: [1] Kondo-lattice semiconductors, [2] superconductivity of f-electron systems, [3] anomalous transport and thermal properties of 4f- and 5f-compounds, [4] low-carrier heavy-electron systems and [5] theoretical investigation of heavy-electron and mixed-valence states. This division of topics has been retained in the organization of papers in this volume. Almost all of the invited and contributed papers are included. These papers include excellent reviews of both the recent advances and historical background of each topic. We believe this book would be a tutorial text for researchers working in the field of solid state physics.
By browsing about 10 000 000 scientific articles of over 200 major journals mainly in a 'cover to cover approach' some 200 000 publications were selected. The extracted data is part of the following fundamental material research fields: crystal structures (S), phase diagrams (also called constitution) (C) and the comprehensive field of intrinsic physical properties (P). This work has been done systematically starting with the literature going back to 1900. The above mentioned research field codes (S, C, P) as well as the chemical systems investigated in each publication were included in the present work. The aim of the Inorganic Substances Bibliography is to provide researchers with a comprehensive compilation of all up to now published scientific publications on inorganic systems in only three handy volumes.