Evolution of magnetism and superconductivity in CeCu{sub 2}(Si{sub 1{minus}x}Ge{sub x}){sub 2}

Journal Article · Tue Jul 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.678· OSTI ID:531822

Trovarelli, O ^[1]; Weiden, M; Mueller-Reisener, R ^[2]; Gomez-Berisso, M ^[1]; Gegenwart, P; Deppe, M; Geibel, C ^[2]; Sereni, J G ^[1]; Steglich, F ^[2]

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1. Centro Atomico Bariloche (CNEA), 8400 S.C. de Bariloche (Argentina)
2. Institut fuer Festkoerperphysik, T.H. Darmstadt, Hochschulstrasse 8, D-64289, Darmstadt (Germany)

We have determined the magnetic phase diagram of CeCu{sub 2}(Si{sub 1{minus}x}Ge{sub x}){sub 2} using specific heat, susceptibility, and resistivity measurements and additional thermal expansion and muon spin resonance experiments. The system evolves continuously from the heavy-fermion state at x=0 to an antiferromagnetically (AF) ordered state at x=1, though the magnetic structure undergoes significant modifications. The results strongly suggest that the AF ordering emerges from the A phase of pure CeCu{sub 2}Si{sub 2}. The phase diagram can be divided into three regions: Low Ge content (x{le}0.2) leads to an enhancement of the A phase of pure CeCu{sub 2}Si{sub 2} and to a moderate decrease of the Kondo temperature. Despite this increase of the magnetic character, we could observe superconductivity up to x=0.1. At large Ge content (x{gt}0.5) the behavior resembles that of pure CeCu{sub 2}Ge{sub 2}. The intermediate region is characterized by the appearance of a second magnetic transition below T{sub N}, which seems to be of first-order type. The appearance of this transition leads to a well-defined critical point at x=0.3 and suggests the possibility of another critical point at x{approx_equal}0.5. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 531822
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 2 Vol. 56; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
CERIUM ALLOYS
COPPER ALLOYS
CRITICAL TEMPERATURE
ELECTRIC CONDUCTIVITY
FERMIONS
GERMANIUM ALLOYS
GERMANIUM SILICIDES
KONDO EFFECT
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MAGNETISM
MUON PROBES
NEEL TEMPERATURE
PHASE DIAGRAMS
SILICON ALLOYS
SPECIFIC HEAT
SUPERCONDUCTIVITY
THERMAL EXPANSION
TRANSITION TEMPERATURE
TYPE-II SUPERCONDUCTORS