Anomalous compressibility effects and superconductivity of EuFe2As2 under high pressures

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Journal of Physics: Condensed Matter

DOI:https://doi.org/10.1088/0953-8984/22/29/292202· OSTI ID:988252

Uhoya, Walter ^[1]; Tsoi, Georgiy ^[1]; Vohra, Y. K. ^[1]; McGuire, Michael A ^[2]; Sefat, A. S. ^[3]; Sales, Brian C ^[2]; Mandrus, David ^[2]; Weir, S. T. ^[4]

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1. University of Alabama, Birmingham
2. ORNL
3. Oak Ridge National Laboratory (ORNL)
4. Lawrence Livermore National Laboratory (LLNL)

The crystal structure and electrical resistance of structurally layered EuFe{sub 2}As{sub 2} have been studied up to 70 GPa and down to a temperature of 10 K, using a synchrotron x-ray source and designer diamond anvils. The room temperature compression of the tetragonal phase of EuFe{sub 2}As{sub 2} (I4/mmm) results in an increase in the a-axis length and a rapid decrease in the c-axis length with increasing pressure. This anomalous compression reaches a maximum at 8 GPa and the tetragonal lattice behaves normally above 10 GPa, with a nearly constant c/a axial ratio. The rapid rise in the superconducting transition temperature (T{sub c}) to 41 K with increasing pressure is correlated with this anomalous compression, and a decrease in T{sub c} is observed above 10 GPa. We present P-V data or the equation of state for EuFe{sub 2}As{sub 2} both in the ambient tetragonal phase and in the high pressure collapsed tetragonal phase up to 70 GPa.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 988252
• Journal Information: Journal of Physics: Condensed Matter, Journal Name: Journal of Physics: Condensed Matter Journal Issue: 29 Vol. 22; ISSN 0953-8984; ISSN 1361-648X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
43 PARTICLE ACCELERATORS
AXIAL RATIO
COMPRESSIBILITY
COMPRESSION
CRYSTAL STRUCTURE
DIAMONDS
ELECTRIC CONDUCTIVITY
SUPERCONDUCTIVITY
SYNCHROTRONS
TETRAGONAL LATTICES
TRANSITION TEMPERATURE
X-RAY SOURCES