Pressure Effect on the Structural and Magnetic Transition in CaFe_2As_2

Shiliang Li; Ying Chen; Jeffrey Lynn; X. H. Chen; Pengcheng Dai

Pressure Effect on the Structural and Magnetic Transition in CaFe$_2$As$_2$

ORAL

Abstract

We use neutron scattering technique to study both the structural and magnetic phase transitions of CaFe$_2$As$_2$. We confirmed that the nuclear structure changes from orthorhombic to collapsed tetragonal phase with increasing pressure at low temperatures. Strong hysteresis is found in increasing and decreasing temperature processes. The c-axis lattice constant of the orthorhombic phase is found to increase with deceasing temperature under pressure while that of the collapsed tetragonal phase shows almost no change, which suggests a strong magnetic-lattice coupling.

March 17, 2009, 12:51 PM – March 17, 2009, 1:03 PM

Authors

Shiliang Li
- Department of Physics and Astronomy, The University of Tennessee
- University of Tennessee, Knoxville
- University of Tennessee
Ying Chen
- NCNR and Univ. of Maryland
- NIST Center for Neutron Research, National Institute of Standards and Technology
- NIST Center for Neutron Research, University of Maryland
Jeffrey Lynn
- NIST Center for Neutron Research
X. H. Chen
- University of Science and Technology
- USTC
Pengcheng Dai
- Oak Ridge National Laboratory
- Univ of Tennessee, Knoxville
- University of Tennessee, Knoxville
- Univ. of Tennessee and NSSD-ORNL
- University of Tennessee, Oak Ridge National Laboratory