Abstract
Isovalent nonmagnetic d(10) and d(0) B″ cations have proven to be a powerful tool for tuning the magnetic interactions between magnetic B' cations in A(2)B'B″O(6) double perovskites. Tuning is facilitated by the changes in orbital hybridization that favor different superexchange pathways. This can produce alternative magnetic structures when B″ is d(10) or d(0). Furthermore, the competition generated by introducing mixtures of d(10) and d(0) cations can drive the material into the realms of exotic quantum magnetism. Here, Te(6+) d(10) was substituted by W(6+) d(0) in the hexagonal perovskite Ba(2)CuTeO(6), which possesses a spin ladder geometry of Cu(2+) cations, creating a Ba(2)CuTe(1-x)W(x)O(6) solid solution (x = 0-0.3). We find W(6+) is almost exclusively substituted for Te(6+) on the corner-sharing site within the spin ladder, in preference to the face-sharing site between ladders. The site-selective doping directly tunes the intraladder, J(rung) and J(leg), interactions. Modeling the magnetic susceptibility data shows the d(0) orbitals modify the relative intraladder interaction strength (J(rung)/J(leg)) so the system changes from a spin ladder to isolated spin chains as W(6+) increases. This further demonstrates the utility of d(10) and d(0) dopants as a tool for tuning magnetic interactions in a wide range of perovskites and perovskite-derived structures.