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تسجيل مستخدم جديدNMR study of the Mott transitions to superconductivity in the two Cs_3C_60 phases
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We report an NMR and magnetometry study on the expanded intercalated fulleride Cs_3C_60 in both its A15 and face centered cubic structures. NMR allowed us to evidence that both exhibit a first-order Mott transition to a superconducting (SC) state, occuring at distinct critical pressures p_c and temperatures T_c. Though the ground state magnetism of the Mott phases differs, their high $T$ paramagnetic and SC properties are found similar, and the phase diagrams versus unit volume per C_60 are superimposed. Thus, as expected for a strongly correlated system, the inter-ball distance is the relvevant parameter driving the electronic behavior and quantum transitions of these systems.
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Former extensive studies of superconductivity in the textit{A}$_{3}$C$_{60}$ compounds, where textit{A} is an alkali, have led to consider that Bardeen Cooper Schrieffer (BCS) electron-phonon pairing prevails in those compounds, though the incidence
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