Phase transitions competition between superconducting

Some needle-shaped crystals of a -TTF[Pd(dmit)2]2 [lc,ld,27] are also isostructural with TTF[Ni(dmit)2]2-This phase also undergoes a metal-to-insulator transition at around 220 K. However, this transition is completely reversible and shows no hysteresis [27]. The effect of high pressure is the suppression of this metal-to-insulator transition. The superconducting transition is observed at 5.93 K and 24 kbar [Id]. A gradual localization of the carriers is observed at low pressure, which can be related to a charge density wave condensation evidenced by X-ray diffuse scattering experiments [23]. a -TTF[Pd(dmit)2]2 is the first example in which competition between CDW and superconductivity is observed. 

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