(Pb,Sr,Cu)Sr_2(Ca,Sr0Cu_2O_y(Pb-1212) and (Pb,Sr,Cu)Sr_2(Ca,Sr)_2Cu_3O_y(Pb-1223) are high-T_c superconducting compounds having commensuratwe and incommensurate modulated structure, respectively(1). Modulated structures are characterized ythe periodic deviation of the atomic position and/or the occupation from the average value. The ratio of modulation wavelength of the periodicity of basic structure is aninteger for commensurate meodulated structures, i.e. superstructures, while for incommensurate modulated structures is an irrrational number. Incommensurate modulated structure can be described as a three-dimensional section of a high-dimensional periodic structure(2). In the present paper, it is reported that both commensurate modulated structure of Pb-1212 and incommensurate modulated structure of Pb-1223 were determined by usinmg the two-stage image processing technique (3) which consits of image deconvolution and phase extension.
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