Layer-stripes in charge-ordered La1-xCaxMnO3 (x=1/3, 1/2, and 2/3)

摘要

Using atomistic simulation we investigated another possible and energetically stable charge- ordering model in La1-xCaxMnO3 ( x = 1/3, 1/2, and 2/3): the layer- stripe model, which can coexist with other charge- ordering models and may be a general phenomenon in these compounds. As x increases from 1/3 to 1/2 then to 2/3, the stability of charge ordering increases, which agrees well with experimental results. The stability of the layer- stripe will reduce when its thickness increases; this may be due to the increase of Jahn - Teller distortions. It is also found that the internal structures ( lattice spacing and Jahn Teller distortion) of layer- stripes are inhomogeneous.