Charge fluctuations across the pressure-induced quantum phase transition in EuCu2(Ge1-x Six)2

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F20%3A00535336" target="_blank" >RIV/68378271:_____/20:00535336 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11320/20:10411352

Result on the web

<a href="https://doi.org/10.1103/PhysRevB.101.205127" target="_blank" >https://doi.org/10.1103/PhysRevB.101.205127</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.101.205127" target="_blank" >10.1103/PhysRevB.101.205127</a>

Result language

angličtina

Original language name

Charge fluctuations across the pressure-induced quantum phase transition in EuCu2(Ge1-x Six)2

Original language description

Pressurizing strategically selected compositions of the EuCu2(Ge1-xSix)(2) series affords an opportunity for gaining microscopic insight into the ground-state properties and interplay between magnetism and valence fluctuations across a quantum critical point. This is investigated by way of systematic Eu-151 Mossbauer spectroscopy measurements on x = 0 and x = 0.5 compositions in the series, pressurized up to 7 GPa including variable temperature scans in the range 300-4.2 K. In EuCu2Ge2 the temperature and pressure dependences of the hyperfine interaction parameters indicate that both the magnetic and divalent state, Eu nu+ where nu = 2, are stable up to 6-7 GPa, thus serving as a useful reference. Whereas in the x = 0.5 composition which initially involves Eu2+, collapse of the magnetically ordered state is onset at similar to 1.3 GPa and there is emergence of a nonmagnetic intermediate valence state coexisting with the magnetically ordered state. This regime of mixed states is a precursor of a quantum phase transition to a nonmagnetic homogeneous intermediate valence state nu similar to 2.45, across a quantum critical point at 3.6 GPa, suggesting a first-order phase transition. X-ray-diffraction pressure studies at 300 K up to 6 GPa of the x = 0.5 composition indicate there is no change in lattice symmetry from the tetragonal ThCr2Si2-type structure. There are also no obvious discontinuities in pressure dependences of the lattice parameters upon evolving through the quantum critical point at 3.6 GPa. Increasing pressure changes the starting Eu2+ valence monotonically, until the mean valence attains its largest value nu similar to 2.45 indicative of enhanced charge fluctuations at the quantum critical point and plateaus thereafter. High-pressure resistance measurements at low temperatures down to 40 mK near the quantum critical point reveal no evidence for superconductivity.n

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

<a href="/en/project/LM2018096" target="_blank" >LM2018096: Materials Growth and Measurement Laboratory</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physical Review B

ISSN

2469-9950

e-ISSN

—

Volume of the periodical

101

Issue of the periodical within the volume

20

Country of publishing house

US - UNITED STATES

Number of pages

10

Pages from-to

1-10

UT code for WoS article

000533497100007

EID of the result in the Scopus database

2-s2.0-85085839937