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Dielectric properties of compositionally graded Ba 1– x Sr x TiO 3 thin films described by the transverse‐field Ising model
Author(s) -
Gao Y. H.,
Cao H. X.,
Jiang Q.
Publication year - 2004
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200402081
Subject(s) - dielectric , materials science , condensed matter physics , ising model , transverse plane , polarization (electrochemistry) , thin film , doping , composite material , optoelectronics , nanotechnology , chemistry , physics , structural engineering , engineering
This investigation reports on the phase transition and dielectric properties of compositionally graded Ba 1– x Sr x TiO 3 (BST) thin films with x decreasing from 0.20 to 0.10 in successive slabs, based on the transverse‐field Ising model (TIM) within the framework of mean field theory. The random bond model of related parameters is applied to mimic doping. The effect on polarization and dielectric susceptibility arising from a gradient in composition is taken into account. The peaks of dielectric susceptibility versus temperature become comparatively flat by modulating appropriate thickness in each slab in compositionally graded BST thin films, which means that the thickness may weaken the effect of composition gradient. When increasing the number of slabs of thin films, the dielectric susceptibility shows good temperature stability in a wide temperature range, which is useful for reducing the temperature coefficient of dielectric susceptibility without depressors. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)