Stacking faults and microstrain in La 1.85M 0.15CuO 4 ( M = Ca, Ba, Sr) by analyzing X-ray diffraction line broadening

Abstract

We obtained x-ray diffraction patterns for three oxides: La 1.85M 0.15CuO 4 ( M= Ca, Ba, Sr). The superconductors show zero-resistance T c values of 19, 28, and 36 K, respectively. Diffraction- line profiles were fit with a convolution of specimen and instrumental functions. The specimen line-broadening angular dependence was analyzed by the Warren-Averbach method of real Fourier coefficients. Stacking-fault probability increases with increasing T c; microstrain decreases.