Neutron diffraction study and anomalous negative thermal expansion in non-superconducting PrFe1-xRuxAsO

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.86.054111· OSTI ID:1049096

Yiu, Yuen ^[1]; Garlea, Vasile O ^[1]; McGuire, Michael A ^[1]; Huq, Ashfia ^[1]; Mandrus, David ^[1]; Nagler, Stephen E ^[1]

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1. ORNL

Neutron powder diraction has been used to investigate the structural and magnetic behavior of the isoelectronically doped Fe pnictide material PrFe1-xRuxAsO. Substitution of Ru for Fe sup- presses the structural and magnetic phase transitions that occur in the undoped compound PrFeAsO. Contrary to the behavior usually observed in 1111 pnictide materials, the suppression of both the structural and magnetic transitions does not result in the emergence of superconductivity or any other new ground state. Interestingly, PrFeAsO itself shows an unusual negative thermal expansion (NTE) along the c-axis, from 60K down to at least 4K; this does not occur in superconducting samples such as those formed by doping with fluorine on the oxygen site. We nd that NTE is present for all concentrations of PrFe1-xRuxAsO with x ranging from 0.05 to 0.75. These results suggest that the absence of superconductivity in these materials could be related to the presence of NTE.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1049096
• Journal Information: Physical Review B, Vol. 86, Issue 5; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
FLUORINE
GROUND STATES
NEUTRON DIFFRACTION
NEUTRONS
OXYGEN
PNICTIDES
SUPERCONDUCTIVITY
THERMAL EXPANSION