title: Superconductivity in Alkaline Earth-Substituted La2CuO4-y.
abstract: La(2)CuO4-y ceramics containing a few percent of Ca(2+), Sr(2+), and Ba(2+) ions have been prepared. Resistivity and susceptibility measurements exhibit superconductive onsets (as in earlier Ba(2+)-containing samples). The onset temperature La(2)CuO4-y with Sr(2+) is higher and its superconductivity-induced diamagnetism larger than that found with Ba(2+) and Ca(2+). This is proof that the electronic change resulting from alkaline earthdoping, rather than the size effect, is responsible for superconductivity. The ionic radius of Sr(2+) is close to that of La(3+) for which it presumably substitutes.
authors.forename: J G
authors.initials: JG
authors.lastname: Bednorz
authors.forename: K A
authors.initials: KA
authors.lastname: Müller
authors.forename: M
authors.initials: M
authors.lastname: Takashige