High temperature superconductivity in air quenched YBa sub 2 Cu sub 3 O sub 7 minus. delta. doped with Sb sub 2 O sub 3

The superconducting properties of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} compounds doped with Sb{sub 2}O{sub 3} have been studied by x-ray diffraction and electrical and magnetic measurements. It is found that the widely accepted procedure of slow cooling or annealing at 600 {degree}C for several hours for oxygenation is not essential to obtain superconductivity in these doped samples. Superconducting transition (92 K) was obtained by directly quenching the doped specimen from the sintering temperature of 950 {degree}C. Tetragonal to orthorhombic transformation has taken place within this short period, indicating that the rate of oxygen absorption has been increased tremendously by Sb{sub 2}O{sub 3} addition in the YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} compound. Undoped samples quenched in air were always tetragonal and nonsuperconducting.