Perovskite LaPbMSbO6 (M=Co, Ni): Structural distortion, magnetic and dielectric properties

XRD Rietveld refinement result of LaPbCoSbO6 presented a large BO6 octahedral distortion along the ab plane. Based upon the variations from Co-O-Sb bond angles, a fierce competition from many extended magnetic coupling routes (M-O-O-M) would induce a considerably large magnetic frustration and electron hopping restriction.