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Giriat, G., Z. Ren, P. Pedrazzini, and D. Jaccard. "High pressure investigation of superconducting signatures in CeCu2Si2: ac-magnetic susceptibility, ac-heat capacity, resistivity and thermopower." Solid State Communications 209–210 (2015): 55–58.
Abstract: Taking advantage of a novel multiprobe setup we have measured, on a unique sample, the ac-magnetic susceptibility, the resistivity, the ac-specific heat and the thermopower of the superconductor heavy fermion CeCu2Si2 under pressure up to 5.1 GPa. At the superconducting transition temperature Tc, the Meissner signal corresponds to that expected for the sample volume and coincides with the specific heat jump and the resistive transition completion temperatures. Differing from previous observations, here the susceptibility measurements did not reveal any anomaly in the vicinity of the resistive transition onset.
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Pedrazzini, P., and D. Jaccard. "The critical pressure of chromium." Physica B: Condensed Matter 403, no. 5-9 (2008): 1222–1224.
Abstract: We present first results of high-pressure resistivity measurements on pure chromium. Two pieces of evidence show that spin density wave magnetism is suppressed at a critical pressure pc?10GPa, namely, the evolution of the ordering temperature TN(p) and the rapid decrease of the residual resistivity close to pc. Our discussion profits from the comparison between pressurized-Cr and the Cr1-xVx alloy, for which a large amount of information on its electronic properties is available.
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Pedrazzini, P., D. Jaccard, M. Deppe, C. Geibel, and J. G. Sereni. "Multiprobe high-pressure experiments in CePd0.6Rh0.4 and CePd3." Physica B: Condensed Matter 404, no. 19 (2009): 2898–2903.
Abstract: Results of recent multiprobe high-pressure experiments on ferromagnetic CePd0.6Rh0.4 and intermediate-valent CePd3 are presented. Simultaneous resistivity (ρ), thermopower (S), and ac heat capacity measurements show that the long-range ferromagnetic state of CePd0.6Rh0.4 vanishes in the proximity of a sharp valence-crossover pressure , i.e. before reaching a quantum critical point. However, a magnetic signal that is progressively suppressed is still detected at higher pressures. For CePd3, the results of simultaneous ρ(T,p) and S(T,p) measurements up to and down to the mK temperature range show a surprisingly weak pressure dependence.
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Seyfarth, G., D. Jaccard, P. Pedrazzini, A. Krzton-Maziopa, E. Pomjakushina, K. Conder, and Z. Shermadini. "Pressure cycle of superconducting Cs0.8Fe2Se2 : A transport study." Solid State Communications 151, no. 10 (2011): 747–750.
Abstract: We report measurements of the temperature and pressure dependence of the electrical resistivity (Ï) of single-crystalline iron-based chalcogenide Cs0.8Fe2Se2. In this material, superconductivity with a transition temperature Tc~30K source develops from a normal state with extremely large resistivity. At ambient pressure, a large “hump†in the resistivity is observed around 200 K. Under pressure, the resistivity decreases by two orders of magnitude, concomitant with a sudden Tc suppression around pc~30K. Even at 9 GPa a metallic resistivity state is not recovered, and the Ï(T) “hump†is still detected. A comparison of the data measured upon increasing and decreasing the external pressure leads us to suggest that the superconductivity is not related to this hump.
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