摘要
We present measurements of Mn L-edge resonant soft X-ray scattering on single-layered manganites with different sizes of cations. Orbital ordering of Pr 0.5 Ca 1.5 MnO 4 exhibits a stronger three-dimensional character and a dramatically enhanced transition temperature, as compared with those of La 0.5 Sr 1.5 MnO 4 . The c-axis correlation length of orbital ordering in Pr 0.5 Ca 1.5 MnO 4 is about half of the in-plane correlation length. Our results indicate that reduction in one-electron bandwidth and quenched disorder strongly enhances the stabilization of charge-orbital ordering. © 2006.