Abstract
The results of x-ray diffraction, electrical resistance, DC and AC magnetization studies on two specimens of compositions Y2.1Ba3.9Cu6O14 and Y1.8Ba4.2Cu6O14 are presented. Our studies confirm that La3Ba3Cu6O14 type ortnornombic phase is responsible for superconductivity in 90K range. The heat treatment that yields high quality samples with sharp transition in electrical resistance as well as in AC magnetic susceptibility measurements is described. Magnetic response just below Tc is found to be sensitive to the measuring field.