DOCSLIB.ORG

MAGNETORESISTIVITY and QUANTUM CRITICALITY in HEAVY FERMION SUPERCONDUCTOR Ce1−Xybxcoin5

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
MAGNETORESISTIVITY and QUANTUM CRITICALITY in HEAVY FERMION SUPERCONDUCTOR Ce1−Xybxcoin5 MAGNETORESISTIVITY AND QUANTUM CRITICALITY IN HEAVY FERMION SUPERCONDUCTOR Ce1−xYbxCoIn5 A dissertation submitted to Kent State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy by Derek J. Haney August, 2016 Dissertation written by Derek J. Haney B.S., University of Akron, Akron, OH, 2010 M.A., Kent State University, Kent, OH, 2013 Approved by Carmen Almasan, Ph.D., Chair, Doctoral Dissertation Committee James Gleeson, Ph.D., Members, Doctoral Dissertation Committee Almut Schroeder, Ph.D., Robin Selinger, Ph.D. Accepted by James Gleeson, Ph.D., Chair, Department of Physics James L. Blank, Ph.D., Dean, College of Arts and Sciences ii TABLE OF CONTENTS LIST OF FIGURES . v LIST OF TABLES . xiv Acknowledgments . xv 1 Introduction . 1 1.1 Heavy Fermions . 1 1.1.1 Kondo Effect . 3 1.1.2 Ruderman-Kittel-Kasuya-Yosida Interaction . 7 1.2 Quantum Criticality . 9 1.2.1 Fermi Liquid Theory . 11 1.2.2 Non-Fermi Liquid Behavior Due to Quantum Criticality . 13 1.3 Magnetoresistivity in Heavy Fermions . 15 1.4 CeCoIn5 .................................. 16 1.4.1 CeIn3 and CeM In5 ........................ 16 1.4.2 Ce1−xYbxCoIn5 .......................... 26 2 Experimental Details . 32 2.1 Sample Growth and Preparation . 32 2.2 Physical Property Measurement System . 33 2.3 Helium-3 Option . 36 2.4 Electrical Transport Measurement . 38 iii 2.5 Pressure . 40 2.6 Magnetoresistivity . 45 2.7 Heat Capacity Measurement . 46 3 Pressure Studies of the Quantum Critical Alloy Ce0:93Yb0:07CoIn5 . 49 3.1 Introduction . 49 3.2 Experimental results and discussion . 51 3.3 Conclusions . 64 4 Quantum Criticality and Gap Structure in Ce1−xYbxCoIn5 . 67 4.1 Introduction . 67 4.2 Experimental results and discussion . 69 4.3 Conclusions . 79 5 Magnetoresistivity Study of the Kondo Impurity to Kondo Lattice Crossover in Ce1−xYbxCoIn5 .......................... 80 5.1 Introduction . 80 5.2 Experimental results and discussion . 81 5.3 Conclusions . 93 6 Summary and Outlook . 94 BIBLIOGRAPHY . 99 iv LIST OF FIGURES 1.1 Magnetic resistivity per mole cerium of CexLa1−xCu6 for different dop- ings. Data per Onuki and Komatsubara (1987) [5]. 5 1.2 Indirect exchange interaction J at interatomic spacing a between local moments due to Friedel oscillations of the conduction electron spin density. 8 1.3 Doniach phase diagram, showing TK and TRKKY with changing ex- change interaction J, and illustrating the resulting phases of magnetic order, Fermi liquid, and (possible) superconductivity around a critical Jc. ..................................... 10 1.4 (a) Low temperature T − g phase diagram of typical quantum crit- ical system where g is a tuning parameter, such as field H, pres- sure P , or doping x. (b) Exponent value " of temperature depen- " dence of ρ(T ) / T for YbRh2Si2 for different temperatures and fields. Applied field B is parallel to the c-axis of the crystal. Graph from Custers, et al. 2003) [33]. 14 1.5 Unit cell crystal structure of CeM In5 (M = Co, Rh, or Ir). Figure from Ref. [43]. 18 v 1.6 Figure compiled from Ref. [14]. (a) Temperature dependent resistiv- ity ρ and magnetic susceptibility χ = M=H of CeCoIn5. Open circles represent χ with H k c and open squares represent χ with H ? c. The inset to (a) shows zero-field-cooled χ (circles, left axis) measured in 10 Oe and resistivity (triangles, right axis) in the vicinity of the super- conducting transition. (b) Specific heat C=T for CeCoIn5 at applied fields of H = 0 and H = 50 kOe. The nuclear Schottky contribution (due to a large nuclear quadrupole of In) has been subtracted. The inset to (b) shows the resulting entropy as a function of temperature. 20 1.7 An H − T phase diagram of CeCoIn5 from Ref. [49] showing the ex- istence of a QCP at approximately HQCP = 5:1 T. The solid squares show the temperature/field at which ρ crossed over from NFL ρ / T to FL ρ / T 2. The filled circles show the location of a peak in the field dependence of the magnetoresistance of CeCoIn5. The inset shows the divergence of A, which is from the low-temperature, high-field Fermi 2 liquid resistivity ρ(T ) = ρ0 + AT ..................... 23 vi 1.8 From Ref. [53]. Phase diagram for CeCoIn5 at low temperatures, dis- playing the superconducting phase and the antiferromagnetic phase within the vortex cores. (a) T − P phase diagram at zero field. Nega- tive pressure measurements from Ref. [54], where a negative chemical pressure was obtained by doping CeCoIn5 with cadmium on the in- dium sites. (b) H − P phase diagram at zero temperature, illustrating the quantum critical line. The red line is from Hu and collaborator's calculations [53], and the dotted yellow line is the result of applying theory from Ref. [55] and using parameters derived by Hu et al. (c) H − T phase diagram at zero pressure showing the superconducting dome with the AFM region within it. The inset shows the same at chemically negative pressure (due to cadmium doping), showing that at negative pressures, the superconducting dome is contained within the AFM region rather than the other way around. 25 1.9 From Ref. [59]. Superconducting transition temperature Tc and coher- ence temperature Tcoh plotted as a function of residual resistivity ρ0 for different doping levels of Ce1−xRxCoIn5. Closed symbols represent Tc and open symbols represent Tcoh. The grey upward-pointing tri- angles on the left represent x = 0, i.e., pure CeCoIn5. Regardless of the nature of the dopant, Tc and Tcoh are each suppressed to zero with increasing x (with x / ρ0). 27 vii 1.10 From Ref. [62]. (a) Field dependence of transverse magnetoresistance of CeCoIn5 for different temperatures. Inset shows that of (nominal) Ce0:6Yb0:4CoIn5, which lacks the strong coherent behavior at low field that CeCoIn5 displays. (b) Temperature dependence of Hmax, which is the field value of the peaks in (a), which is where coherent behavior gives way to single-ion behavior. (c) H − x phase diagram illustrating the behavior of HQCP vs. doping. Inset shows Tc and Tcoh at different doping levels of Ce1−xYbxCoIn5 and Ce1−xLaxCoIn5. 28 2.1 (a) A cross-sectional view of the PPMS sample chamber showing its components. (b) A cutaway view of the sample chamber showing the puck with sample at the bottom of the sample chamber. 35 2.2 A schematic showing the use of the T-shaped platform in order to align the c axis of the sample parallel to the applied magnetic field. 37 2.3 (a) A schematic of the four-terminal sensing method. (b) A photograph of a sample in our lab in which we are applying the four-terminal sensing method. 39 2.4 A photograph of a half-assembled pressure cell. 41 2.5 Photographs of a wired feedthrough. (a) Image of the feedthrough, showing the wires coming out of the back. (b) Close-up of the sample on top of the platform. (c) Side view of the platform with the tin manometer on the left and the sample on the right. 44 2.6 A side view of the heat capacity setup. 47 viii 3.1 (a) Resistivity ρa of Ce0:93Yb0:07CoIn5 as a function of temperature T for different pressures P (0, 2.7, 5.1, 7.4, and 8:7 kbar). The arrow at the maximum of the resistivity data marks the coherence temperature Tcoh. (b) Evolution of Tcoh as a function of pressure P . Inset: Super- conducting critical temperature Tc as a function of pressure P . The solid lines are guides to the eye. 53 p 3.2 (a) Fits of the resistivity ρa(P; T ) = ρa0(P ) + A(P )T + B(P ) T for different pressures on Ce0:93Yb0:07CoIn5 over the temperature range 3 K ≤ T ≤ 15 K. (b) Pressure P dependence of the linear T contribu- p tion A and T contribution B, obtained from fits of the resistivity data shown in panel (a). (c) Pressure P dependence of the residual resistivity ρa0, obtained from the fits. 56 p 3.3 (a) Resistivity ρa of Ce0:93Yb0:07CoIn5 as a function of T , in the temperature range 1:8 K ≤ T ≤ 5 K. The solid lines are linear fits of p ∗ the data with ρa(P; T ) = ρa0(P ) + B (P ) T for 1:8 K ≤ T ≤ 5 K. In- p ∗ set: Pressure P dependence of the coefficient B . (b) ρa vs T of Ce0:92Yb0:08CoIn5 measured in zero magnetic field and at 4 T. The 4 T data has been offset upwards by 5 µΩ cm for visual clarity. 58 ix 3.4 Magnetic field H dependence (plotted as function of H2) of magne- toresistivity (MR) ∆ρa/ρa(H = 0) ≡ [ρa(H) − ρa(H = 0)]/ρa(H = 0)] of Ce0:93Yb0:07CoIn5 measured at two different temperatures and am- bient pressure. The dashed line in the main figures marks Hmax, cor- responding to the coherence giving way to single-ion Kondo behavior. Inset: MR data vs H2 measured under 5:1 kbar. The red line shows the quadratic regime of MR. 61 3.5 Temperature T dependence of the maximum in magnetoresistivity Hmax for different pressures P . The solid lines below 10 K are linear fits to the data. 63 3.6 Pressure P dependence of residual resistivity ρa0 (obtained through the fitting of the resistivity data as discussed in the text), normalized to its value at zero pressure (right vertical axis) and P dependence of inverse slope of Hmax(T ) normalized to its value at zero pressure (left vertical axis). 65 4.1 (a) Normalized resistivity ρ(T )/ρ(300 K) of Ce1−xYbxCoIn5 (x = 0:09 and 0:16) as a function of temperature T .
Load more

Recommended publications
  • Science Journals
    SCIENCE ADVANCES | RESEARCH ARTICLE PHYSICS Copyright © 2019 The Authors, some Orbital-selective Kondo lattice and enigmatic f electrons rights reserved; exclusive licensee emerging from inside the antiferromagnetic phase American Association for the Advancement of a heavy fermion of Science. No claim to original U.S. Government 1 1 1 2,3 4 Works. Distributed Ioannis Giannakis , Justin Leshen , Mariam Kavai , Sheng Ran *, Chang-Jong Kang , under a Creative 2,3 2,5 2 2 6,7 6 Shanta R. Saha , Y. Zhao ,Z.Xu*, J. W. Lynn , Lin Miao , L. Andrew Wray , Commons Attribution 4,8 2,3 1† Gabriel Kotliar , Nicholas P. Butch , Pegor Aynajian NonCommercial License 4.0 (CC BY-NC). Novel electronic phenomena frequently form in heavy-fermions because of the mutual localized and itinerant na- ture of f-electrons. On the magnetically ordered side of the heavy-fermion phase diagram, f-moments are expected to be localized and decoupled from the Fermi surface. It remains ambiguous whether Kondo lattice can develop inside the magnetically ordered phase. Using spectroscopic imaging with scanning tunneling microscope, complemented by neutron scattering, x-ray absorption spectroscopy, and dynamical mean field theory, we probe Downloaded from the electronic states in antiferromagnetic USb2. We visualize a large gap in the antiferromagnetic phase within which Kondo hybridization develops below ~80 K. Our calculations indicate the antiferromagnetism and Kondo lattice to reside predominantly on different f-orbitals, promoting orbital selectivity as a new conception into how these phenomena coexist in heavy-fermions. Finally, at 45 K, we find a novel first order–like transition through abrupt emergence of nontrivial 5f-electronic states that may resemble the “hidden-order” phase of URu2Si2.
    [Show full text]
  • Heavy-Fermion Superconductivity in Cecoin5 at 2.3 K
    Heavy-fermion superconductivity in CeCoIn5 at 2.3 K C. Petrovic1, P.G. Pagliuso2, M.F. Hundley2, R. Movshovich2, J.L. Sarrao2, J.D. Thompson2, Z. Fisk1,2, and P. Monthoux3 1National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306 USA 2Condensed Matter and Thermal Physics, Los Alamos National Laboratory, Los Alamos, NM 87545 USA 3Cavendish Laboratory, University of Cambridge, Cambridge CB3 OHE, UK Abstract We report the observation of heavy-fermion superconducitivity in CeCoIn5 at Tc=2.3 K. When compared to the pressure-induced Tc of its cubic relative CeIn3 (Tc~200 mK), the Tc of CeCoIn5 is remarkably high. We suggest that this difference may arise from magnetically mediated superconductivity in the layered crystal structure of CeCoIn5. Superconductivity is distinct in the correlation often evident between structure and properties: certain crystal structures or substructures favor superconductivity.1 In particular, what underlies this relationship in the high-Tc cuprates and heavy-Fermion materials, which border so closely on magnetically ordered phases, is of essential interest both fundamentally and in the search for new superconducting materials.2,3 For example, fully half of the known heavy-Fermion superconductors crystallize in the tetragonal ThCr2Si2 structure, which is also the structure type of the La2CuO4 family of high-Tc superconductors.4 In the cuprates, there is no consensus on the origin of superconductivity, but their quasi-2D structure and proximity to magnetic order have been shown to be particularly favorable for an unconventional form of superconductivity in which a pairwise attractive interaction among quasiparticles is mediated by magnetic correlations.5 Here, we report the discovery of a possible heavy-Fermion analogue of the cuprates, a new layered superconductor CeCoIn5, with the highest known ambient- pressure superconducting transition temperature Tc in the class of heavy-Fermion materials.
    [Show full text]
  • 1 Introduction
    Catalysis, Heavy Fermions, Solitons, Cold Fusion, Low Energy Nuclear Reactions (LENR) and all that M. W. Kalinowski IMDIK PAN Pracownia Bioinformatyki ul. Pawi´nskiego5, 02-106 Warsaw, Poland e-mails: markwkalbioexploratorium.pl, mkalinowskiimdik.pan.pl, phone: +48228499358 To the memory of my friend Stanis law Radzki, a chemist with wide horizons Abstract. We consider in the paper an idea of a soliton and heavy fermion catalysis for a cold fusion similar to a muon catalysis. This catalysis is achieved via quasi- chemical bonds for heavy fermions and solitons as well. We consider also a soliton catalysis (for KP-solutions), which is quite different. This kind of catalysis is similar to enzymatic catalysis. In the paper we construct a model for a cold fusion reactor based on Onsager{Prigogine irreversible thermodynamics. We give examples of several compounds with heavy fermions (heavy electrons) which are hydrogen storages. Samples of those compounds can be (in principle) cold fusion reactors if filled with a deuter. It is necessary to do several experiments (de- scribed in the paper) in order to find a proper compound which will be a base for a battery device. We consider also a case with cold plasma (e.g. in metals) filled with a deuter. Solitons in a plasma can catalyse a fusion in two regimes: as quasiparticles and in enzymatic-like regime. Key words: solitons, heavy fermions, cold fusion, catalysis, hydrogen storage, low energy nuclear reactions, chemically assisted nuclear reactions, quasi-chemical bonds, KdV equation, plasma physics, KP equations, Onsager{Prigogine principle, deuter, quasiparticles. 1 Introduction In the paper we consider three types of catalysis for a cold fusion: heavy fermion, 1-soliton and n-soliton.
    [Show full text]
  • Unconventional Superconductivity in Heavy Fermion Systems
    Heavy Fermion Material with Kondo Lattice Heavy Fermions and Strong Correlation Strong Correlated Phenomena Unconventional Superconductivity in Heavy Fermion Systems Changkai Zhang Fakult¨atf¨urPhysik Ludwig-Maximilians-Universit¨atM¨unchen High-Tc Superconductivity January 27, 2020 F. Steglich, S. Wirth, Rep. Prog. Phys. 79 084502 (2016) P. Coleman, Heavy Fermions, arXiv:cond-mat/0612006 Changkai Zhang (LMU M¨unchen) Heavy Fermion Superconductivity 1/24 Heavy Fermion Material with Kondo Lattice Heavy Fermions and Strong Correlation Strong Correlated Phenomena Table of Contents 1 Heavy Fermion Material with Kondo Lattice Magnetic Impurities and Kondo Effect Kondo Lattice and Localized Fermions 2 Heavy Fermions and Strong Correlation Electric Band Structure Emergence of Strong Correlation 3 Strong Correlated Phenomena Unconventional Superconductivity Existence of Quantum Critical Point Changkai Zhang (LMU M¨unchen) Heavy Fermion Superconductivity 2/24 Heavy Fermion Material with Kondo Lattice Magnetic Impurities and Kondo Effect Heavy Fermions and Strong Correlation Kondo Lattice and Localized Fermions Strong Correlated Phenomena Table of Contents 1 Heavy Fermion Material with Kondo Lattice Magnetic Impurities and Kondo Effect Kondo Lattice and Localized Fermions 2 Heavy Fermions and Strong Correlation Electric Band Structure Emergence of Strong Correlation 3 Strong Correlated Phenomena Unconventional Superconductivity Existence of Quantum Critical Point Changkai Zhang (LMU M¨unchen) Heavy Fermion Superconductivity 3/24 Heavy Fermion Material with Kondo Lattice Magnetic Impurities and Kondo Effect Heavy Fermions and Strong Correlation Kondo Lattice and Localized Fermions Strong Correlated Phenomena Magnetic Impurities and Kondo Effect The resistance unexpectedly increases as temperature decreases in Cu and Au-specimens. Figure: W. J. de Haas, G. J. van den Berg, Physica vol.3 (1936) The resistance versus temperature of pure Au.
    [Show full text]
  • Optical Spectroscopy Shows That the Normal State of Uru2si2 Is an Anomalous Fermi Liquid U
    Optical spectroscopy shows that the normal state of URu2Si2 is an anomalous Fermi liquid U. Nagel ∗,T. Uleksin ∗ , T. R~o~om ∗ ,R.P.S.M. Lobo y, P. Lejay z, C.C. Homes x, J. Hall {, A.W. Kinross { , S. Purdy { , T.J.S. Munsie { , T.J. Williams { , G.M. Luke { k, and T. Timusk { k ∗National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia,yLPEM, ESPCI-ParisTech, UPMC, CNRS, 10 rue Vauquelin, 75005 Paris, France,zInstitut Ne´el,CNRS/UFJ, BP 166, 38042 Grenoble Cedex 9, France,xCondensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11780, USA;,{Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada;, and kThe Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada. Submitted to Proceedings of the National Academy of Sciences of the United States of America Fermi showed that electrons, as a result of their quantum nature, den order transition, has an infrared spectrum consisting of a form a gas of particles where the temperature and density follow narrow Drude peak and a strong incoherent background. The the so called Fermi distribution. In a metal, as shown by Landau, large electronic specific heat just above the transition pointed that despite their strong Coulomb interaction with each other and ∗ to the presence of heavy carriers with a mass m = 25me [2]. the positive background ions, the electrons continue to act like free However recent scanning tunneling microsocopy experiments quantum mechanical particles but with enhanced masses. This state of matter, the Landau-Fermi liquid, is recognized experimentally by contradict this model[12, 13].
    [Show full text]
  • Metallic Ferromagnetism in the Kondo Lattice
    Metallic ferromagnetism in the Kondo lattice Seiji J. Yamamotoa and Qimiao Sib,1 aNational High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310-3706; and bDepartment of Physics and Astronomy, Rice University, Houston, TX 77005 Communicated by M. Brian Maple, University of California, San Diego, La Jolla, CA, June 30, 2010 (received for review April 15, 2010) Metallic magnetism is both ancient and modern, occurring in such may then lead to an itinerant ferromagnet (23). With the general familiar settings as the lodestone in compass needles and the hard limitations of the Stoner approach in mind, here we carry out an drive in computers. Surprisingly, a rigorous theoretical basis for me- asymptotically exact analysis of the ferromagnetic state. We are tallic ferromagnetism is still largely missing. The Stoner approach able to do so by using a reference point that differs from either perturbatively treats Coulomb interactions when the latter need to the Stoner or Nagaoka approach (24), and accessing a ferromag- be large, whereas the Nagaoka approach incorporates thermody- netic phase whose excitations are of considerable interest in the namically negligible holes into a half-filled band. Here, we show context of heavy fermion ferromagnets. We should stress that a that the ferromagnetic order of the Kondo lattice is amenable to ferromagnetic order may also arise in different regimes of related an asymptotically exact analysis over a range of interaction para- models, such as in one dimension (25) or in the presence of meters. In this ferromagnetic phase, the conduction electrons and mixed-valency (26). 1 S local moments are strongly coupled but the Fermi surface does not Our model contains a lattice of spin-2 local moments ( i for enclose the latter (i.e., it is “small”).
    [Show full text]
  • FAR-INFRARED OPTICAL PROPERTIES of the HEAVY FERMION SUPERCONDUCTOR UBE13 by Adan Brown B.Sc
    FAR-INFRARED OPTICAL PROPERTIES OF THE HEAVY FERMION SUPERCONDUCTOR UBE13 By Adan Brown B.Sc. Physics A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE In THE FACULTY OF MATHEMATICS AND SCIENCE DEPARTMENT OF PHYSICS We accept this thesis as conforming to the required standard BROCK UNIVERSITY September, 2001 © Adan Brown, 2001 Acknowledgement I would like to extend my sincere gratitude to Dr. Maureen Reedyk for her great support and insight throughout these years. Her dedication, effort, and tremendous patience has played a key role in the successful completion of this thesis. I would also like to thank the rest of the faculty for their contribution, not only toward this thesis but also for my undergraduate education. Special thanks to Dr. Razavi and Dr. Mitrovic for their support and encouragement. Some of those harsh, but well deserved words, I will never forget. I like to thank as well Dr. Shukla for his devotion and the numerous conversations we had to further develop my education. I find it important to also thank other people whose efforts underlie every research project done here at the university. I would like to thank the members of the machine and electronic shops, as well as the people in charge of maintaining the liquid nitrogen system. With out them our experiments couldn't have been completed. Thanks to Dr. Timusk and staff for allowing us to perform experiments and for taking the time to show us the ropes in their laboratory. Also, J. L. Smith at Los Alamos for providing the samples.
    [Show full text]
  • Heavy Fermion Material: Ce Versus Yb Case
    Heavy fermion material: Ce versus Yb case J Flouquet 1, H Harima 2 1/ INAC/SPSMS, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble, France 2/ Department of Physics, Graduate School of Science, Kobe University, Kobe, Hyogo 657-8501, Japan Abstract: Heavy fermion compounds are complex systems but excellent materials to study quantum criticality with the switch of different ground states. Here a special attention is given on the interplay between magnetic and valence instabilities which can be crossed or approached by tuning the system by pressure or magnetic field. By contrast to conventional rare earth magnetism or classical s-wave superconductivity, strong couplings may occur with drastic changes in spin or charge dynamics. Measurements on Ce materials give already a sound basis with clear key factors. They have pointed out that close to a magnetic or a valence criticality unexpected phenomena such as unconventional superconductivity, non Fermi liquid behaviour and the possibility of re- entrance phenomena under magnetic field. Recent progresses in the growth of Yb heavy fermion compounds give the perspectives of clear interplays between valence and magnetic fluctuations and also the possibility to enter in new situations such as valence transitions inside a sole crystal field doublet ground state. 1/ Introduction motion, a phenomenon absent in the case of the 3He neutral atom. The interest in heavy fermion materials started three decades ago with the discovery that in a compound (CeAl 3) (1) (figure 1) the extrapolation of the Sommerfeld coefficient γ of the ratio S/T of the entropy (S) by the temperature (T) reaches a value γ near 1 J·mole -1K-2 i.e.
    [Show full text]
  • Searching for Heavy Fermion Materials in Ce Intermetallic Compounds Jinke Tang Iowa State University
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1989 Searching for heavy fermion materials in Ce intermetallic compounds Jinke Tang Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Condensed Matter Physics Commons Recommended Citation Tang, Jinke, "Searching for heavy fermion materials in Ce intermetallic compounds " (1989). Retrospective Theses and Dissertations. 9247. https://lib.dr.iastate.edu/rtd/9247 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS The most advanced technology has been used to photo­ graph and reproduce this manuscript from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are re­ produced by sectioning the original, beginning at the upper left-hand corner and continuing from left to right in equal sections with small overlaps.
    [Show full text]
  • Quantum Criticality in the Heavy-Fermion Superconductor Cecoin5
    Quantum Criticality in the Heavy-Fermion Superconductor CeCoIn5 by Johnpierre Paglione A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Graduate Department of Physics University of Toronto Copyright °c 2005 by Johnpierre Paglione Abstract Quantum Criticality in the Heavy-Fermion Superconductor CeCoIn5 Johnpierre Paglione Doctor of Philosophy Graduate Department of Physics University of Toronto 2005 The study of quantum phase transitions has received a large amount of attention ow- ing to the fact that a range of anomalous properties appear to be linked to the occurrence of quantum fluctuations. CeCoIn5 is a recently discovered heavy-fermion metal with an unconventional superconducting state below Tc = 2:3 K and a range of properties unex- plained by the conventional Fermi liquid theory of metals. As a member of the CeMIn5 family (where M = Co, Ir or Rh), the anomalous transport, magnetic and thermody- namics properties of CeCoIn5 are thought to arise from an antiferromagnetic instability which has yet to be identi¯ed. This study reports measurements of heat and charge transport in CeCoIn5, as a func- tion of temperature T , magnetic ¯eld H and orientation of current J with respect to the crystal axes, which have unearthed a host of incredible properties. These include the identi¯cation of a ¯eld-tuned quantum critical point (QCP) which coincides with the upper critical ¯eld of the superconducting state at Hc2 = 5 T. As evidenced by divergences of the T 2 coe±cients of both electrical and thermal resistivities in the ¯eld- induced Fermi liquid state, the nature of this QCP is further elucidated by the observed relation between ¢H=T scaling and an anomalous T 2=3 dependence of resistivity in the ii high-¯eld non-Fermi liquid regime of J ? [001] transport.
    [Show full text]
  • Pressure Tuning of Magnetic Fluctuation and Superconductivity in Heavy Fermion Materials
    Condensed Matter Seminar PRESSURE TUNING OF MAGNETIC FLUCTUATION AND SUPERCONDUCTIVITY IN HEAVY FERMION MATERIALS Prof. Carmen Almasan, Department of Physics, Kent State University Thursday, February 14 4:00 P.M. 184 NSH One of the greatest challenges to Landau’s Fermi liquid theory –the standard theory of metals –is presented by complex materials with strong electronic correlations. The non-Fermi liquid transport and thermodynamic properties of these materials are often explained by the presence of strong quantum critical fluctuations associated with a quantum phase transition that happens at a quantum critical point (QCP). The heavy-fermion material CeCoIn5 is a prototypical system for which its pronounced non-Fermi liquid behavior in the normal state and unconventional superconductivity are thought to arise from the proximity of this system to a QCP [1-5]. Previous experiments address the physics of this QCP by extrapolating results obtained in the normal state, i.e., there were no direct probes of antiferromagnetism and quantum criticality in the superconducting state. This motivated us to study the transport in the mixed state, thus revealing the physics of antiferromagnetism and quantum criticality of the underlying normal state [6]. In this talk I will present the results obtained in these studies by measuring the vortex core dissipation under applied hydrostatic pressure (P). The vortex core resistivity increases sharply with decreasing magnetic field (H) and temperature (T) due to quasiparticle scattering on critical antiferromagnetic fluctuations. This behavior is greatly suppressed with increasing P. Using our experimental results, we obtained an explicit equation for the antiferromagnetic boundary inside the superconducting dome and constructed an H- T-P phase diagram.
    [Show full text]
  • Heavy-Fermion Superconductivity in Cecoin5 at 2.3 K
    INSTITUTE OF PHYSICS PUBLISHING JOURNAL OF PHYSICS: CONDENSED MATTER J. Phys.: Condens. Matter 13 (2001) L337–L342 www.iop.org/Journals/cm PII: S0953-8984(01)23561-9 LETTER TO THE EDITOR Heavy-fermion superconductivity in CeCoIn5 at 2.3 K C Petrovic1,PGPagliuso2, M F Hundley2, R Movshovich2, J L Sarrao2, J D Thompson2, Z Fisk1,2 and P Monthoux3 1 National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306, USA 2 Condensed Matter and Thermal Physics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA 3 Cavendish Laboratory, University of Cambridge, Cambridge CB3 OHE, UK Received 29 March 2000 Abstract We report the observation of heavy-fermion superconductivity in CeCoIn5 at Tc = 2.3 K. When compared to the pressure-induced Tc of its cubic relative CeIn3 (Tc ∼ 200 mK), the Tc of CeCoIn5 is remarkably high. We suggest that this difference may arise from magnetically mediated superconductivity in the layered crystal structure of CeCoIn5. Superconductivity is distinct in the correlation often evident between structure and properties: certain crystal structures or substructures favour superconductivity [1]. In particular, what underlies this relationship in the high-Tc cuprates and heavy-fermion materials, which border so closely on magnetically ordered phases, is of essential interest both fundamentally and in the search for new superconducting materials [2, 3]. For example, fully half of the known heavy- fermion superconductors crystallize in the tetragonal ThCr2Si2 structure, which is also the structure type of the La2CuO4 family of high-Tc superconductors [4]. For the cuprates, there is no consensus on the origin of the superconductivity, but their quasi-2D structure and proximity to magnetic order have been shown to be particularly favourable for an unconventional form of superconductivity in which a pairwise-attractive interaction among quasiparticles is mediated by magnetic correlations [5].
    [Show full text]