Mazumder, Ranabrata and Sen, Amarnath (2009) Coexistence of Strong Frequency Dispersion of Dielectric Constant and Temperature-Invariant Curie Peaks in Doped Ferroelectric Ceramics. Japanese Journal Of Applied Physics, 48 (12). Article No.-121401. ISSN 0021-4922

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Abstract

We report an unusual dielectric behavior of acceptor (copper)-doped barium titanate, where along with sharp temperature-invariant Curie peaks, a frequency dispersion, which is much stronger than that of a normal ferroelectric material has been observed. The value of gamma (exponent of modified Curie-Weiss law) has been found to be 1.5 at 1 kHz, which is intermediate to those of a ferroelectric and a relaxor material. However, at 1 MHz frequency, gamma is equal to 1 similar to a normal ferroelectric. The simple reasoning of additive coupling of ferroelectricity and Maxwell-Wagner relaxation falls short of explaining these observations. Such behaviour can be understood by considering the role of an impressed local ac field across the grain boundaries of the samples, the field being generated from the alternating space charge polarization at low frequencies. (C) 2009 The Japan Society of Applied Physics

Item Type:	Article
Uncontrolled Keywords:	BARIUM-TITANATE CERAMICS; LEAD MAGNESIUM NIOBATE; PIEZOELECTRIC CERAMICS; RELAXOR BEHAVIOR; THIN-FILMS; SPECTROSCOPY; RELAXATION; BI-SRTIO3; PHASE
Subjects:	Physical Properties Electronics Engineering Materials
Divisions:	UNSPECIFIED
Depositing User:	Ashok K Podder
Date Deposited:	31 Jan 2012 11:57
Last Modified:	01 Apr 2016 05:59
URI:	http://cgcri.csircentral.net/id/eprint/566

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