Tuning dielectric properties in ceramics with anisotropic grain structure: The effect of sintering temperature on BaLa4Ti4O15
authors Mahajan, A; Reaney, IM; Vilarinho, PM
nationality International
journal MATERIALS & DESIGN
author keywords Microwave materials; Dielectrics; BaLa4Ti4O15; Anisotropy; Raman; Sintering
keywords PEROVSKITE-RELATED COMPOUNDS; COMPOSITE CERAMICS; THICK-FILMS; MICROSTRUCTURE; PERMITTIVITY; (BA
abstract The orientation and grain aspect ratio, size and distribution of BaLa4Ti4O15 (BLT) ceramics have been studied as a function of sintering temperature with a view to elucidating a general principle by which the microwave properties (MW) can be understood/tuned in systems which exhibit anisotropic grain structures. For BLT sintered at 1500 degrees C, epsilon(r) reaches a maximum of 51, with tan delta minimum at 0.002 and tau(epsilon r) = -17 ppm/degrees C but epsilon(r) subsequently varies non-linearly as sintering temperature increases. Since epsilon(r) and tau(epsilon r) are directly proportional in the absence of a phase transition, the variation of tau(epsilon r) as a function of the sintering temperature is also nonlinear. This behaviour is related with variations in the orientation and grain aspect ratio, size and distribution with the sintering temperature and it is demonstrated that by controlling sintering conditions, microwave dielectric properties can be tuned. It is proposed that this is a general phenomenon which can also be used to explain the variation and tune the properties of other ceramic systems with anisotropic grain structures. (C) 2016 Elsevier Ltd. All rights reserved.
publisher ELSEVIER SCI LTD
issn 0264-1275
year published 2017
volume 113
beginning page 377
ending page 383
digital object identifier (doi) 10.1016/j.matdes.2016.10.040
web of science category Materials Science, Multidisciplinary
subject category Materials Science
unique article identifier WOS:000389142800044
  ciceco authors
  impact metrics
times cited (wos core): 2
journal impact factor (jcr 2016): 4.364
5 year journal impact factor (jcr 2016): 4.498
category normalized journal impact factor percentile (jcr 2016): 83.818
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