Abstract
We studied the isotope, pressure and doping effects on the pseudogap temperature T* by neutron spectroscopic experiments of the relaxation rate of crystal-field excitations in La1.96-xSrxHo0.04CuO4 (x = 0.11, 0.15, 0.20, 0.25) on the high-resolution time-of-flight spectrometer FOCUS at SINQ, PSI. We found clear evidence for the opening of a pseudogap in the underdoped regime at T*(x = 0.11) = (82.2 ± 1.2) K as well as in the overdoped and the heavily overdoped compounds at T*(x = 0.2) = (49.2 ± 0.7) K and at T*(x = 0.25) = (46.5 ± 0.5) K, respectively. Furthermore, we investigated the effect of oxygen isotope substitution on the pseudogap, the experiments revealed ΔT*(x = 0.11) = (21.3 ± 5.2) K and ΔT*(x = 0.2) = (4.5 ± 1.3) K. The application of hydrostatic pressure (0.8 and 1.2 GPa) on the optimally doped compound (x = 0.15) results in a downward shift of dT*/dp = (-5.9 ± 1.6) K/GPa.
Original language | English |
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Pages (from-to) | 415-420 |
Number of pages | 6 |
Journal | Progress in Solid State Chemistry |
Volume | 35 |
Issue number | 2-4 SPEC. ISS. |
DOIs | |
State | Published - 2007 |
Externally published | Yes |
Funding
This work was performed at the Swiss Spallation Neutron Source SINQ, Paul Scherrer Institut (PSI), Villigen, Switzerland. Stimulating discussions with K.A. Müller and M. Sigrist as well as financial support by the Swiss National Science Foundation through both the Project No. 20-66948.01 and the NCCR MaNEP project are gratefully acknowledged.
Funders | Funder number |
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Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | 20-66948.01 |
Keywords
- High-temperature superconductors
- Neutron scattering
- Pseudogap