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Grain‐Boundary‐Phase Identification of a Lead‐Based Relaxor by X‐ray Photoelectron Spectroscopy
Author(s) -
Kanai Hideyuki,
Yoshiki Masahiko,
Hayashi Masaru,
Kuwae Ryosho,
Yamashita Yohachi
Publication year - 1994
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1994.tb07128.x
Subject(s) - grain boundary , materials science , x ray photoelectron spectroscopy , ceramic , dielectric , phase (matter) , phase boundary , dissolution , analytical chemistry (journal) , grain boundary diffusion coefficient , mineralogy , composite material , chemical engineering , microstructure , chemistry , environmental chemistry , optoelectronics , organic chemistry , engineering
X‐ray photoelectron spectroscopy was used to study a lead‐based relaxor dielectric ceramic to identify the grain‐boundary phase most likely to be responsible for the insulation degradation of relaxor dielectric ceramics under humid loading conditions. The grain‐boundary phase consisted mainly of lead and oxygen. The binding energies of Pb4f 7/2 and O1s in the grain‐boundary phase were found to be 137.3 eV and 528.8 eV, respectively, and these values agreed well with those for Pb 3 O 4 and PbO 2 . In addition, the broadness of the Pb4f 7/2 peak suggested the presence of PbO. Measurements were made of lead dissolution from dielectric ceramics in hot water; specimens with a grain‐boundary phase gave a 30 to 50 times greater lead concentration in the hot water than specimens without a grain‐boundary phase. This demonstrated that the grain‐boundary phase easily dissolved in hot water. Thus, it was concluded that the grain‐boundary phase contained water‐soluble PbO 2 and PbO. The results strongly supported the resistance degradation mechanism of relaxor dielectric ceramics under humid loading conditions as previously proposed by the authors.