Combined effects of Sr substitution and pressure on the ground states in
- J.W. Goethe-Univ. Frankfurt(M), Frankfurt(M) (Germany)
- Ames Lab. and Iowa State Univ., Ames, IA (United States); Univ. of California, San Diego, CA (United States)
- San Diego State Univ., San Diego, CA (United States)
- Ames Lab. and Iowa State Univ., Ames, IA (United States)
Here, we present a detailed study of the combined effects of Sr substitution and hydrostatic pressure on the ground-state properties of CaFe2As2. Measurements of the electrical resistance and magnetic susceptibility, both at ambient and finite pressure P ≤ 2 GPa, were performed on Ca1–xSrxFe2As2 single crystals grown out of Sn flux. We find that by Sr substitution the transition temperature to the magnetic/structural phase is enhanced and therefore a higher pressure is needed to suppress the transition to lowest temperature. In addition, the transition to the collapsed tetragonal phase is found at a pressure, which is distinctly higher than in the pure compound. This implies that the stability ranges of both phases shift on the pressure-axis upon doping, but the latter one with a higher rate. These observations suggest the possibility of separating the two phase lines, which intersect already at elevated temperatures for x = 0 and low Sr concentration levels. For x = 0.177, we find strong evidence that both phases remain separated down to the lowest temperature and that a zero-resistance state emerges in this intermediate pressure window. This observation indicates that Sr substitution combined with hydrostatic pressure provides another route for stabilizing superconductivity in CaFe2As2. Lastly, our results are consistent with the notion that (i) preserving the fluctuations associated with the structural-magnetic transition to low temperatures is vital for superconductivity to form in this material and that (ii) the nonmagnetic collapsed tetragonal phase is detrimental for superconductivity.
- Research Organization:
- Ames Laboratory (AMES), Ames, IA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-07CH11358
- OSTI ID:
- 1335025
- Alternate ID(s):
- OSTI ID: 1329508
- Report Number(s):
- IS-J-9130; PRBMDO
- Journal Information:
- Physical Review B, Vol. 94, Issue 14; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Evolution of the magnetic order of Fe and Eu sublattices in Eu 1− x Ca x Fe 2 As 2 (0 ⩽ x ⩽ 1) single crystals
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journal | September 2018 |
Collapsed tetragonal phase as a strongly covalent and fully nonmagnetic state: Persistent magnetism with interlayer As–As bond formation in Rh-doped $Ca_{0.8}Sr_{0.2}Fe_{2}As_{2}$
|
text | January 2018 |
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