Pressure dependence of the charge-density-wave and superconducting states in GdTe3, TbTe3, and DyTe3

We present electrical resistivity and ac-susceptibility measurements of GdTe3, TbTe3, and DyTe3 performed under pressure. An upper charge-density-wave (CDW) is suppressed at a rate of dT(CDW),(1)/dP similar to -85 K/GPa. For TbTe3 and DyTe3, a second CDW below T-CDW,(2) increases with pressure until it reaches the T-CDW,(1)(P) line. For GdTe3, the lower CDW emerges as pressure is increased above similar to 1 GPa. As these two CDW states are suppressed with pressure, superconductivity (SC) appears in the three compounds at lower temperatures. Ac-susceptibility experiments performed on TbTe3 provide compelling evidence for bulk SC in the low-pressure region of the phase diagram. We provide measurements of superconducting critical fields and discuss the origin of a high-pressure superconducting phase occurring above 5 GPa.