Hydrostatic pressure effects on the superconductivity of La/sub 1.2-x/Eu/sub x/MO6S8 pseudoternary compounds

The effect of hydrostatic pressure on the superconductivity of La/sub 1.2-x/Eu/sub x/Mo6W8 pseudoternary compounds was studied by means of low-frequency ac and dc magnetic susceptibility measurements up to 20 kbar. The superconducting transition temperature T/sub c/ at ambient pressure is a weakfunction of Eu concentration x for 0< or approx. =x< or approx. =0.2, and then decreases smoothly with x for x>0.2 until superconductivity is completely suppressed for x> or =0.95. Pressure was found to decrease T/sub c/ in the La-rich compounds and to increase T/sub c/ in the Eu-rich compounds. Pressure also induces superconductivity in compounds with x>0.95 that are not superconducting at ambient pressure. A La/sub 0.2/Eu/sub 1.0/Mo6S8 compound revealed a sizeable Meissner effect for pressure larger than 7 kbar