Analysis on insulator-metal transition in yttrium doped LSMO from electron density distribution

Yttrium doped LSMO (La1-xSrxMnO3) was prepared using sol-gel technique and analysed for the insulator-metal transition from charge density variation in the unit cell with respect to different stoichiometric inclusion of yttrium. X-ray powder diffraction profiles of the samples were obtained and the well known Rietveld method and a versatile tool called maximum entropy method (MEM) were used for structural and profile refinement. The charge density in the unit cell was constructed using refined structure factors and was analysed. The charge ordering taking place in the insulator-metal transition was investigated and quantified. The insulator-metal transition was found to occur when 20% of La/Sr atoms were replaced by yttrium. The changes in the charge environment have also been analysed. (author)