Dilatometric approach for the determination of the solid state reaction-onset of the lead based relaxor ferroelectric system

Journal Article · Mon May 26 04:00:00 EDT 2003 · Materials Research Bulletin

DOI:https://doi.org/10.1016/S0025-5408(03)00060-6· OSTI ID:20887971

Bhat, V V; Radhika Rao, M V; Umarji, A M

Dilatometer based thermal expansion studies have been carried out on the starting oxide mixtures of some of the important relaxor ferroelectric compositions including lead iron niobate, lead magnesium niobate-lead titanate and lead zinc niobate-barium titanate. An anomalous thermal expansion behavior is observed between 550 and 650 deg. C corresponding to the onset of the solid state reaction. Further heating of the reaction mixture resulted in a decrease in the dimension of the sample. From the complementary evidence of DTA, X-ray diffraction (XRD) and scanning electron microscopy (SEM), it is shown that the initiation of solid state reaction results in the restructuring of the reacting grains to form the agglomerates of fine particles of reaction intermediates. This phenomenon is shown to be absent in the barium zinc niobate system where the pyrochlore intermediates do not exist. This novel dilatometric approach has been projected as a possible technique to identify optimum calcination temperatures to produce sinter-active powders in the above oxide system, thereby help in reducing the sintering temperatures.

• OSTI ID: 20887971
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 6 Vol. 38; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM
CALCINATION
DIELECTRIC PROPERTIES
DIFFERENTIAL THERMAL ANALYSIS
FERROELECTRIC MATERIALS
IRON
LEAD
MAGNESIUM
NIOBATES
OXIDES
PYROCHLORE
REACTION INTERMEDIATES
SCANNING ELECTRON MICROSCOPY
SINTERING
THERMAL EXPANSION
TITANATES
X-RAY DIFFRACTION
ZINC