skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Pressure dependence of Ce valence in CeRhIn 5

Abstract

We have studied the Ce valence as a function of pressure in CeRhIn5 at 300 K and at 22 K using x-ray absorption spectroscopy in partial fluorescent yield mode. At room temperature, we found no detectable change in Ce valence greater than 0.01 up to a pressure of 5.5 GPa. At 22 K, the valence remains robust against pressure below 6 GPa, in contrast to the predicted valence crossover at P = 2.35 GPa. In conclusion, this work yields an upper limit for the change in Ce-valence and suggests that the critical valence fluctuation scenario, in its current form, is unlikely.

Authors:
ORCiD logo [1];  [2];  [3];  [3];  [3];  [3];  [2];  [4];  [2]
  1. Univ. of California, Davis, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. Univ. of California, Davis, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1415561
Report Number(s):
LLNL-JRNL-691879
Journal ID: ISSN 0953-8984; TRN: US1800838
Grant/Contract Number:
AC52-07NA27344
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Physics. Condensed Matter
Additional Journal Information:
Journal Volume: 30; Journal Issue: 3; Journal ID: ISSN 0953-8984
Publisher:
IOP Publishing
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; heavy-fermion; superconductivity; x-ray spectroscopy

Citation Formats

Brubaker, Z. E., Stillwell, R. L., Chow, P., Xiao, Y., Kenney-Benson, C., Ferry, R., Jenei, Z., Zieve, R. J., and Jeffries, J. R. Pressure dependence of Ce valence in CeRhIn5. United States: N. p., 2017. Web. doi:10.1088/1361-648X/aa9e2b.
Brubaker, Z. E., Stillwell, R. L., Chow, P., Xiao, Y., Kenney-Benson, C., Ferry, R., Jenei, Z., Zieve, R. J., & Jeffries, J. R. Pressure dependence of Ce valence in CeRhIn5. United States. doi:10.1088/1361-648X/aa9e2b.
Brubaker, Z. E., Stillwell, R. L., Chow, P., Xiao, Y., Kenney-Benson, C., Ferry, R., Jenei, Z., Zieve, R. J., and Jeffries, J. R. Thu . "Pressure dependence of Ce valence in CeRhIn5". United States. doi:10.1088/1361-648X/aa9e2b.
@article{osti_1415561,
title = {Pressure dependence of Ce valence in CeRhIn5},
author = {Brubaker, Z. E. and Stillwell, R. L. and Chow, P. and Xiao, Y. and Kenney-Benson, C. and Ferry, R. and Jenei, Z. and Zieve, R. J. and Jeffries, J. R.},
abstractNote = {We have studied the Ce valence as a function of pressure in CeRhIn5 at 300 K and at 22 K using x-ray absorption spectroscopy in partial fluorescent yield mode. At room temperature, we found no detectable change in Ce valence greater than 0.01 up to a pressure of 5.5 GPa. At 22 K, the valence remains robust against pressure below 6 GPa, in contrast to the predicted valence crossover at P = 2.35 GPa. In conclusion, this work yields an upper limit for the change in Ce-valence and suggests that the critical valence fluctuation scenario, in its current form, is unlikely.},
doi = {10.1088/1361-648X/aa9e2b},
journal = {Journal of Physics. Condensed Matter},
number = 3,
volume = 30,
place = {United States},
year = {Thu Dec 14 00:00:00 EST 2017},
month = {Thu Dec 14 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on December 14, 2018
Publisher's Version of Record

Save / Share:
  • We report {sup 115}In nuclear-quadrupole-resonance (NQR) measurements of the pressure (P)-induced superconductor CeRhIn{sub 5} in the antiferromagnetic (AF) and superconducting (SC) states. In the AF region, the internal field H{sub int} at the In site is substantially reduced from H{sub int}=1.75kOe at P=0 to 0.39 kOe at P=1.23GPa, while the Neel temperature slightly changes with increasing P. This suggests that either the size in the ordered moment M{sub Q}(P) or the angle {theta}(P) between the direction of M{sub Q}(P) and the tetragonal c axis is extrapolated to zero at P{sup *}=1.6{+-}0.1GPa at which a bulk SC transition is no longermore » emergent. In the SC state at P=2.1GPa, the nuclear spin-lattice relaxation rate {sup 115}(1/T{sub 1}) has revealed a T{sup 3} dependence without the coherence peak just below T{sub c}, giving evidence for the unconventional superconductivity. The dimensionality of the magnetic fluctuations in the normal state is also discussed.« less
  • CeRhIn{sub 5} is a new heavy-electron material that crystallizes in a quasi-2D structure that can be viewed as alternating layers of CeIn{sub 3} and RhIn{sub 2} stacked sequentially along the tetragonal c axis. Application of hydrostatic pressure induces a first-order-like transition from an unconventional antiferromagnetic state to a superconducting state with T{sub c}=2.1 K . (c) 2000 The American Physical Society.
  • Measurements of the low-temperature specific heat of the intermetallic compounds Ce(Cu/sub 1-x/Ni/sub x/)/sub 5/ (0< or =x< or =0.8) in magnetic fields B = 0--8 T reveal a peak due to localized f electrons of cerium ions. The position of this peak depends on x and B. At x> or =0.6, the peak is not observed; this result is interpreted as evidence that the cerium ions go into a mixed-valence state.
  • Four members of the RE{sub 4}LiGe{sub 4} (RE=La, Ce, Pr, and Sm) system have been prepared by high-temperature reaction method and characterized by X-ray diffractions. All compounds crystallize in the orthorhombic Gd{sub 5}Si{sub 4}-type structure (space group Pnma, Pearson code oP16) with bonding interactions for interslab Ge{sub 2} dimers. The Li substitution for rare-earth elements in the RE{sub 4}LiGe{sub 4} system leads to a combined effect of the increased chemical pressure and the decreased valance electron concentration (VEC), which eventually results in the structure transformation from the Sm{sub 5}Ge{sub 4}-type with all broken interslab Ge–Ge bond for the parental RE{submore » 5}Ge{sub 4} to the Gd{sub 5}Si{sub 4}-type structure for the ternary RE{sub 4}LiGe{sub 4} (RE=La, Ce, Pr, and Sm) system. Site-preference between rare-earth metals and Li is proven to generate energetically the most favorable atomic arrangements according to coloring-problem, and the rationale is provided using both the size-factor and the electronic-factor related, respectively, to site-volume and electronegativity as well as QVAL values. Tight-binding, linear-muffin-tin-orbital (TB-LMTO) calculations are performed to investigate electronic densities of states (DOS) and crystal orbital Hamilton population (COHP) curves. The influence of reduced VEC for chemical bonding including the formation of interslab Ge{sub 2} dimers is also discussed. The magnetic property measurements prove that the non-magnetic Li substitution leads to the ferromagnetic (FM)-like ground state for Ce{sub 4}LiGe{sub 4} and the co-existence of antiferromagntic (AFM) and FM ground states for Sm{sub 4}LiGe{sub 4}. - Graphical abstract: Reported is a combined effect of the chemical pressure and the reduced VEC caused by the smaller monovalent non-magnetic Li substitution for the larger trivalent magnetic rare-earth metals in the RE{sub 4}LiGe{sub 4} (RE=La, Ce, Pr, and Sm) system. This results in the structure transformation from the Sm{sub 5}Ge{sub 4}-type to the Gd{sub 5}Si{sub 4}-type structure and the changes in magnetic properties. Display Omitted - Highlights: • Four Li-containing intermetallic compounds RE{sub 4}LiGe{sub 4} (RE=La, Ce, Pr and Sm) were synthesized. • The combined effect of the chemical pressure and the reduced VEC caused by Li substitution for a rare-earth metal results in the structure transformation. • Electronic structures and magnetic properties of title compounds were thoroughly investigated.« less