학술논문

Propriedades estruturais e microestruturais de manganitas dopadas com cobre
Document Type
article
Source
Química Nova. January 2007 30(7)
Subject
manganites
X-ray diffraction
scanning electron microscopy
Language
Portuguese
ISSN
0100-4042
Abstract
We report a structural study on polycrystalline La0.86Sr0.14Mn1-y Cu yO3+delta samples (y = 0, 0.05, 0.10, 0.15, 0.20) using refinement of powder X-ray diffraction data and analysis of scanning electron microscopy images. It is found that the structure remains rhombohedral through the whole series, with a decrease in the average Mn-Mn bond distances, slight variations in Mn-O-Mn angle and reduction in the unit cell volume with increasing Cu amounts. The values of Mn-Mn distances suggest compact structures with d within ±1%. Scanning electron microscopy images reveal homogeneous microstructure in all samples, besides a trend for smaller grains and larger porosity with increasing Cu content.