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

Title: Experimental studies of the phase transition in YbIn{sub 1{minus}x}Ag{sub x}Cu{sub 4}

Abstract

We report measurements of the low-temperature specific-heat coefficient {gamma}=C{sub p}(T)/T, cell volume V(T), Hall coefficient R{sub H}(T), and valence z=2+n{sub f} [where the Yb hole occupation n{sub f}(T) was determined from Yb-L{sub 3} x-ray absorption] of single crystals of YbIn{sub 1{minus}x}Ag{sub x}Cu{sub 4}. Alloying YbInCu{sub 4} with Ag increases the temperature T{sub s}(x) of the first-order isomorphic phase transition and causes it to terminate at a critical point at x{sub c}=0.195 and T{sub c}=77thinspK. The variation of V(T) near the critical point is well described by a mean-field equation of state. The phase transition involves a large change in the Kondo temperature, and the transition temperatures T{sub s}(x) are of order of the Kondo temperatures T{sub K}{sup +}(x) of the high-temperature state. The cell volume is found to vary proportionally to 1{minus}n{sub f}(T). At low temperatures, well away from the transition, the Wilson ratio of the susceptibility {chi}(0) and specific heat coefficient {gamma} falls within 20{percent} of the value predicted for a Kondo impurity, and 1{minus}n{sub f}(0) and {chi}(0) are roughly proportional as predicted from the Anderson model. The temperature dependence n{sub f}(T) for temperatures away from the phase transition also fits the predictions of the Kondo model. The smallmore » volume discontinuity {Delta}V/V{sub 0} observed at T{sub s} suggests that the phase transition is not due to a Kondo volume collapse. The large Hall coefficients R{sub H}(T) observed for x{lt}x{sub c} and T{gt}T{sub s}(x) suggest instead that a low carrier density in the high-temperature state plays a key role in the phase transition. {copyright} {ital 1997} {ital The American Physical Society}« less

Authors:
;  [1]; ;  [2]; ; ;  [3]; ;  [4]
  1. University of California, Irvine, California 92697 (United States)
  2. Florida State University, Tallahassee, Florida 32306 (United States)
  3. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  4. University of California, Santa Cruz, California 95064 (United States)
Publication Date:
OSTI Identifier:
632598
Resource Type:
Journal Article
Journal Name:
Physical Review, B: Condensed Matter
Additional Journal Information:
Journal Volume: 56; Journal Issue: 13; Other Information: PBD: Oct 1997
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; YTTERBIUM ADDITIONS; PHASE TRANSFORMATIONS; INDIUM ALLOYS; SILVER ALLOYS; COPPER ALLOYS; YTTERBIUM ALLOYS; CARRIER DENSITY; EQUATIONS OF STATE; KONDO EFFECT; MAGNETIC SUSCEPTIBILITY; SPECIFIC HEAT; QUATERNARY ALLOY SYSTEMS; TEMPERATURE DEPENDENCE; HALL EFFECT

Citation Formats

Cornelius, A L, Lawrence, J M, Sarrao, J L, Fisk, Z, Hundley, M F, Kwei, G H, Thompson, J D, Booth, C H, and Bridges, F. Experimental studies of the phase transition in YbIn{sub 1{minus}x}Ag{sub x}Cu{sub 4}. United States: N. p., 1997. Web. doi:10.1103/PhysRevB.56.7993.
Cornelius, A L, Lawrence, J M, Sarrao, J L, Fisk, Z, Hundley, M F, Kwei, G H, Thompson, J D, Booth, C H, & Bridges, F. Experimental studies of the phase transition in YbIn{sub 1{minus}x}Ag{sub x}Cu{sub 4}. United States. https://doi.org/10.1103/PhysRevB.56.7993
Cornelius, A L, Lawrence, J M, Sarrao, J L, Fisk, Z, Hundley, M F, Kwei, G H, Thompson, J D, Booth, C H, and Bridges, F. Wed . "Experimental studies of the phase transition in YbIn{sub 1{minus}x}Ag{sub x}Cu{sub 4}". United States. https://doi.org/10.1103/PhysRevB.56.7993.
@article{osti_632598,
title = {Experimental studies of the phase transition in YbIn{sub 1{minus}x}Ag{sub x}Cu{sub 4}},
author = {Cornelius, A L and Lawrence, J M and Sarrao, J L and Fisk, Z and Hundley, M F and Kwei, G H and Thompson, J D and Booth, C H and Bridges, F},
abstractNote = {We report measurements of the low-temperature specific-heat coefficient {gamma}=C{sub p}(T)/T, cell volume V(T), Hall coefficient R{sub H}(T), and valence z=2+n{sub f} [where the Yb hole occupation n{sub f}(T) was determined from Yb-L{sub 3} x-ray absorption] of single crystals of YbIn{sub 1{minus}x}Ag{sub x}Cu{sub 4}. Alloying YbInCu{sub 4} with Ag increases the temperature T{sub s}(x) of the first-order isomorphic phase transition and causes it to terminate at a critical point at x{sub c}=0.195 and T{sub c}=77thinspK. The variation of V(T) near the critical point is well described by a mean-field equation of state. The phase transition involves a large change in the Kondo temperature, and the transition temperatures T{sub s}(x) are of order of the Kondo temperatures T{sub K}{sup +}(x) of the high-temperature state. The cell volume is found to vary proportionally to 1{minus}n{sub f}(T). At low temperatures, well away from the transition, the Wilson ratio of the susceptibility {chi}(0) and specific heat coefficient {gamma} falls within 20{percent} of the value predicted for a Kondo impurity, and 1{minus}n{sub f}(0) and {chi}(0) are roughly proportional as predicted from the Anderson model. The temperature dependence n{sub f}(T) for temperatures away from the phase transition also fits the predictions of the Kondo model. The small volume discontinuity {Delta}V/V{sub 0} observed at T{sub s} suggests that the phase transition is not due to a Kondo volume collapse. The large Hall coefficients R{sub H}(T) observed for x{lt}x{sub c} and T{gt}T{sub s}(x) suggest instead that a low carrier density in the high-temperature state plays a key role in the phase transition. {copyright} {ital 1997} {ital The American Physical Society}},
doi = {10.1103/PhysRevB.56.7993},
url = {https://www.osti.gov/biblio/632598}, journal = {Physical Review, B: Condensed Matter},
number = 13,
volume = 56,
place = {United States},
year = {1997},
month = {10}
}