Pressure-induced collapsed-tetragonal phase in
- Iowa State Univ., Ames, IA (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
We present high-energy x-ray diffraction data under applied pressures up to p = 29 GPa, neutron diffraction measurements up to p = 1.1GPa, and electrical resistance measurements up to p = 5.9 GPa, on SrCo2As2. Here, our x-ray diffraction data demonstrate that there is a first-order transition between the tetragonal (T) and collapsed-tetragonal (cT) phases, with an onset above approximately 6 GPa at T = 7K. The pressure for the onset of the cT phase and the range of coexistence between the T and cT phases appears to be nearly temperature independent. The compressibility along the a axis is the same for the T and cT phases, whereas, along the c axis, the cT phase is significantly stiffer, which may be due to the formation of an As-As bond in the cT phase. Our resistivity measurements found no evidence of superconductivity in SrCo2As2 for p ≤ 5.9 GPa and T ≥ 1.8 K. The resistivity data also show signatures consistent with a pressure-induced phase transition for p ≳ 5.5 GPa. Single-crystal neutron diffraction measurements performed up to 1.1 GPa in the T phase found no evidence of stripe-type or A-type antiferromagnetic ordering down to 10 K. Spin-polarized total-energy calculations demonstrate that the cT phase is the stable phase at high pressure with a c/a ratio of 2.54. Furthermore, these calculations indicate that the cT phase of SrCo2As2 should manifest either A-type antiferromagnetic or ferromagnetic order.
- Research Organization:
- Ames Laboratory (AMES), Ames, IA (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- FG02-94ER14466; AC02-07CH11358; FG02-99ER45775; AC02-06CH11357; EAR1157758; EAR1128799; NA0001974; AC05-00OR22725
- OSTI ID:
- 1234447
- Alternate ID(s):
- OSTI ID: 1228422; OSTI ID: 1334455
- Report Number(s):
- IS-J-8798; PRBMDO
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 92, Issue 22; ISSN 1098-0121
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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