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Phonons, Q-dependent Kondo spin fluctuations, and 4f phonon resonance in YbAl3

Journal Article · · Physical Review B
 [1];  [1];  [1];  [2];  [3];  [4];  [5];  [6];  [6];  [6]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Univ. of California, Santa Barbara, CA (United States)
  3. Dresden Univ. of Technology (Germany)
  4. Brookhaven National Lab. (BNL), Upton, NY (United States)
  5. Argonne National Lab. (ANL), Argonne, IL (United States)
  6. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
+ Show Author Affiliations
4f intermediate valence (IV) compounds are canonical hosts of correlated electron physics and can contribute to our understanding of the larger class of correlated electron materials. In this work, we study the prototype IV compound YbAl3 which exhibits a nonintegral valence with a moderately heavy fermion ground state and a large Kondo temperature (TK~500–600K). To better characterize the correlated physics of YbAl3, we have measured the phonon and the magnetic excitation spectra on single crystals of this material by time-of-flight inelastic neutron scattering and inelastic x-ray scattering. We have also performed theoretical calculations of the phonon spectra. We present three findings of these measurements. First, we observe that the measured phonon spectra can be described adequately by a calculation based on standard DFT+U density functional theory. The calculated energies, however, are 10% too low compared to the measured energies. This discrepancy may reflect a hardening of the phonons due to dynamic 4f correlations. Second, the low-temperature spin fluctuations on the Kondo energy scale kBTK have a momentum (Q) dependence similar to that seen recently in the IV compound CePd3. For that system, the Q dependence has been attributed to particle-hole excitations in a coherent itinerant 4f correlated ground state. We suggest a similar origin for the momentum dependence seen in YbAl3. This Q dependence disappears as the temperature is raised towards room temperature and the 4f electron band states become increasingly incoherent. Such a coherent/incoherent crossover is expected to be generic for correlated electron systems. Third, a low-temperature magnetic peak observed in the neutron scattering near 30 meV shows dispersion identical to a particular optic-phonon branch. This 4f/phonon resonance disappears for T≥150K. The phonon spectrum appears to be unaffected by the resonance. We discuss several possibilities for the origin of this unusual excitation, which may be unique to YbAl3. We suggest that the excitation may arise from the large amplitude beating of the light Al atoms against the heavy Yb atoms, resulting in a dynamic 4f/3p hybridization.
Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
Swiss National Science Foundation (SNSF); USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-06CH11357; AC05-00OR22725; SC0012704
OSTI ID:
1734525
Alternate ID(s):
OSTI ID: 1735443
Journal Information:
Physical Review B, Journal Name: Physical Review B Journal Issue: 20 Vol. 102; ISSN 2469-9950
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

References (38)

Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set journal July 1996
Phonon line shapes and excitation energies journal June 1997
First-principles investigation of mechanical and thermodynamic properties of the rare earth intermetallic YbAl3 under pressure journal March 2012
Temperature-tunable Fano resonance induced by strong coupling between Weyl fermions and phonons in TaAs journal March 2017
Lifshitz transition from valence fluctuations in YbAl3 journal October 2017
Time-resolved collapse and revival of the Kondo state near a quantum phase transition journal July 2018
Light-induced charge density wave in LaTe3 journal November 2019
Magnetoelastic hybrid excitations in CeAuAl 3 journal March 2019
Q -dependence of the spin fluctuations in the intermediate valence compound CePd 3 journal May 2014
Analysis of line shapes observed in the scattering of thermal neutrons from superfluid He 4 journal February 1979
Neutron-inelastic-scattering study of the compound YbCuAl journal January 1985
Large-orbital-degeneracy expansion for the lattice Anderson model journal March 1987
Pseudoexcitons in mixed-valence metals journal January 1989
Projector augmented-wave method journal December 1994
Paramagnetic scattering from the valence-fluctuation compound YbAl 3 journal October 1994
Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set journal October 1996
Electron-energy-loss spectra and the structural stability of nickel oxide: An LSDA+U study journal January 1998
Slow crossover in Yb X Cu 4 ( X =Ag, Cd, In, Mg, Tl, Zn) intermediate-valence compounds journal January 2001
Anderson lattice behavior in Yb 1 − x Lu x Al 3 journal March 2004
Calculation of the lattice constant of solids with semilocal functionals journal February 2009
Phonon anomalies in α -uranium journal September 2010
Raman scattering investigation of the electron-phonon coupling in superconducting Nd(O,F) BiS 2 journal August 2014
How Bad Metals Turn Good: Spectroscopic Signatures of Resilient Quasiparticles journal February 2013
Observation of f -Band Hybridization Gap in the Anomalous Rare-Earth Compound Yb Al 3 journal April 1985
Two Energy Scales and Slow Crossover in YbAl 3 journal March 2002
Localized Excitation in the Hybridization Gap in YbAl 3 journal March 2006
Fermi-liquid instabilities at magnetic quantum phase transitions journal August 2007
High-energy-resolution inelastic X-ray scattering spectrometer at beamline 30-ID of the Advanced Photon Source journal April 2020
Light-Induced Superconductivity in a Stripe-Ordered Cuprate journal January 2011
Coherent band excitations in CePd 3 : A comparison of neutron scattering and ab initio theory journal January 2018
Metastable ferroelectricity in optically strained SrTiO 3 journal June 2019
Terahertz field–induced ferroelectricity in quantum paraelectric SrTiO 3 journal June 2019
Intermediate Valence Metals journal May 2008
Heavy Fermions in YbAl 3 Studied by the de Haas-van Alphen Effect journal March 2000
Pseudogap Formation and Heavy-Carrier Dynamics in Intermediate-Valence YbAl 3 journal August 2004
Absence of Hybridization Gap in Heavy Electron Systems and Analysis of YbAl 3 in Terms of Nearly Free Electron Conduction Band journal December 2007
Lattice Dynamics of Intermediate Valence Semiconductor SmB 6 journal November 1989
DAVE: A Comprehensive Software Suite for the Reduction, Visualization, and Analysis of Low Energy Neutron Spectroscopic Data
  • Azuah, Richard Tumanjong; Kneller, Larry R.; Qiu, Yiming
  • Journal of Research of the National Institute of Standards and Technology, Vol. 114, Issue 6 https://doi.org/10.6028/jres.114.025
journal November 2009

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