190 research outputs found

    Universal Behavior of Heavy-Fermion Metals Near a Quantum Critical Point

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    The behavior of the electronic system of heavy fermion metals is considered. We show that there exist at least two main types of the behavior when the system is nearby a quantum critical point which can be identified as the fermion condensation quantum phase transition (FCQPT). We show that the first type is represented by the behavior of a highly correlated Fermi-liquid, while the second type is depicted by the behavior of a strongly correlated Fermi-liquid. If the system approaches FCQPT from the disordered phase, it can be viewed as a highly correlated Fermi-liquid which at low temperatures exhibits the behavior of Landau Fermi liquid (LFL). At higher temperatures TT, it demonstrates the non-Fermi liquid (NFL) behavior which can be converted into the LFL behavior by the application of magnetic fields BB. If the system has undergone FCQPT, it can be considered as a strongly correlated Fermi-liquid which demonstrates the NFL behavior even at low temperatures. It can be turned into LFL by applying magnetic fields BB. We show that the effective mass MM^* diverges at the very point that the N\'eel temperature goes to zero. The BTB-T phase diagrams of both liquids are studied. We demonstrate that these BTB-T phase diagrams have a strong impact on the main properties of heavy-fermion metals such as the magnetoresistance, resistivity, specific heat, magnetization, volume thermal expansion, etc.Comment: Revtex, 11 pages, revised and accepted by JETP Let

    Doping effects in the coupled, two-leg spin ladder BiCu2PO6

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    We report preparation, x-ray diffraction, magnetic susceptibility chi(T) and heat capacity Cp(T) measurements on the undoped samples as also samples with Zn-doped (S = 0) at Cu site, Ni doped (S = 1) at Cu site, and Ca-doped (holes) at Bi site in the coupled two-leg spin ladder system BiCu2PO6. While, Zn shows complete solid solubility, Ni could be doped to about 20% and Ca to about 15%. Magnetization and heat capacity data in the undoped compound point towards the existence of frustration effects. In all the samples, the chi(T) at low temperature increases with doping content. The Zn-induced susceptibility is smaller than that due to effective S=1/2 moments possibly due to frustrating next-nearest-neighbor interactions along the leg. For Zn content x > 0.01, chi(T) deviates from the Curie-law at low temperatures. The magnetic specific heat data Cm(T) for the Zn-doped samples show weak anomalies at low temperature in agreement with chi(T) behavior. The anomalies are suggestive of spin freezing at low-T. In contrast, prominent effects are observed in chi(T) and Cm(T) on Ni-doped samples. The zero-field-cooled (ZFC) and field-cooled (FC) chi(T) data are different from each other at low temperature unlike that for Zn doped samples, clearly indicating a transition to a spin-glass like phase. No anomalies were found in Ca- or Pb-doped samples.Comment: 16 pages, 9 figures, Submitted to J. Phy. Cond. Matte

    Design innovation for the 1990's

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    Statement of responsibility on title-page reads: Richard K. Lester, Michael J. Driscoll, Michael W. Golay, David D. Lanning, Lawrence M. Lidsky, Norman C. Rasmussen and Neil E. Todreas"September 1983."Includes bibliographical reference

    Plasmas and Controlled Nuclear Fusion

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    Contains reports on five research projects.U. S. Atomic Energy Commission (Contract AT(30-1)-3980

    Plasmas and Controlled Nuclear Fusion

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    Contains reports on eleven research projects split into three section.U. S. Atomic Energy Commission (Contract AT(30-1)-3980

    Plasma Dynamics

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    Contains reports on three research projects.Wright Air Development Division (Contract AF33(616)-3984)United States Atomic Energy Commission (Contract AT(30-1)-1842)National Science Foundation (Grant G-9330)United States Air Force, Air Force Cambridge Research Center (Contract AF19(604)-4551)United States Air Force, Air Force Cambridge Research Center, Air Research and Development Command (Contract AF19(604)-5992

    Applied Plasma Research

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    Contains reports on three research projects.National Science Foundation (Grant GK-18185)M. I. T. Lincoln Laboratory Purchase Order No. CC-55

    Plasma Dynamics

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    Contains reports on three research projects.National Science Foundation (Grant G-9330)United States Air Force, Air Force Cambridge Research Center (Contract AF19(604)-5992)United States ArmyUnited States Air Force (Contract AF19(604)-7400)Lincoln Laboratory (Purchase Order B-00306)Flight Accessories Laboratory, Wright-Patterson Air Force Base (WADD Contract AF33(616)-7624)United States Air Force, Air Force Cambridge Research Laboratories (Contract AF19(604)-4551)United States NavyUnited States Atomic Energy Commission (Contract AT(30-1)-1842
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