Variation in the structural and magnetic properties induced by La doping in Pr(Br_1-xLa_x)₂Cu₃O_7+y

Neutron diffraction and ac magnetic susceptibility measurements were performed to study the effects of La doping on the structural and magnetic properties of polycrystalline Pr(Ba_1-xLa_x)₂Cu₃O_7+y. Structural studies using high-resolution neutron diffraction and Rietveld analysis indicate that La doping triggers the occupation of O on the antichain sites which reduces the degree of orthorhombicity in the system. Tetragonal symmetry was observed in the 29% La-doped compound. Magnetic orderings of the Pr ions as well as the Cu ions were evident in the susceptibility. The Pr spin ordering was confirmed by the neutron magnetic diffraction data. Significant reductions in the ordering temperature of Pr were found upon increased La doping, while the spin configuration remained. No obvious changes were observed in the ordering temperature of Cu.