Formation of collapsed tetragonal phase in EuCo2As2 under high pressure

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

OSTI ID:990245

Bishop, Mattew ^[1]; Uhaya, Walter ^[2]; Tsoi, Georgiy ^[2]; Vohra, Yogesh ^[2]; Safa-Sefat, Athena ^[3]; Sales, Brian C ^[3]

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1. University of West Georgia, Carrollton
2. University of Alabama, Birmingham
3. ORNL

The structural properties of EuCo{sub 2}As{sub 2} have been studied up to 35 GPa, through the use of x-ray diffraction in a diamond anvil cell at a synchrotron source. At ambient conditions, EuCo{sub 2}As{sub 2} (I4/mmm) has a tetragonal lattice structure with a bulk modulus of 48 {+-} 4 GPa. With the application of pressure, the a axis exhibits negative compressibility with a concurrent sharp decrease in c-axis length. The anomalous compressibility of the a axis continues until 4.7 GPa, at which point the structure undergoes a second-order phase transition to a collapsed tetragonal (CT) state with a bulk modulus of 111 {+-} 2 GPa. We found a strong correlation between the ambient pressure volume of 122 parents of superconductors and the corresponding tetragonal to collapsed tetragonal phase transition pressures.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 990245
• Journal Information: Journal of Physics: Condensed Matter, Journal Name: Journal of Physics: Condensed Matter Journal Issue: 42 Vol. 22
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
COMPRESSIBILITY
DIAMONDS
EUROPIUM COMPOUNDS
PRESSURE DEPENDENCE
PRESSURE RANGE GIGA PA
SUPERCONDUCTORS
SYNCHROTRONS
TETRAGONAL LATTICES
X-RAY DIFFRACTION