True Tolerance Factor Effects in Ln3+1.85M2+0.15CuO4 Superconductors

A series of seven Ln3+1.85M2+0.15CuO4 samples has been prepared in which mixtures of Ln=La and Nd and M=Ca, Sr, and Ba are used to increase the average radius from 1.180 to 1.223 ? (equivalent to an increase of tolerance factor from 0.856 to 0.871) while the size variance is fixed at a constant value of sigma2=0.0020 ?2. X-ray powder diffraction is used to study structural changes, and ac magnetic susceptibility, electrical resistivity, and thermoelectric power measurements show the variation of physical properties as a true function of the tolerance factor