Choudhury, P Roy and Krupanidhi, SB (2008) Dielectric response of $BaZrO_3/BaTiO_3$ and $SrTiO_3/BaZrO_3$ superlattices. In: Jorunal of Applied Physics, 104 (11). pp. 114105-1.
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Dielectric materials with high tunability, low loss, and desired range of permittivity are an attractive class of materials for a variety of applications in microwave components such as tunable filters, phase shifters, antennas, etc. In this article, we have investigated the low frequency dielectric properties of $BaZrO_3/BaTiO_3$ and $SrTiO_3/BaZrO_3$ superlattices of varying modulation periods for the potential application toward electrically tunable devices. The dielectric response of the superlattices as a function of temperature revealed remarkable stability for both types of superlattices, with no observed dielectric anomalies within that range. Dielectric losses were also nominally low with minimal variation within the measured temperature range. Sufficiently high tunability of \sim 40% was observed for the $BaZrO_3/BaTiO_3$ superlattices at the lowest individual layer thicknesses. In comparison, the $SrTiO_3/BaZrO_3$ superlattices showed a minimum tunability for lowest period structures. It showed maximum tunability of \sim 20% at 10 kHz and room temperature at an intermediate dimension of 3.85 nm periodicity superlattice. The tunability value degraded with increasing as well as decreasing periodicities for the $SrTiO_3/BaZrO_3$ superlattices. The dielectric response has been explained on the basis of size effects, interlayer coupling between dissimilar materials, domain contribution, and depolarizing electric fields.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to American Institue of Physics.|
|Department/Centre:||Division of Chemical Sciences > Materials Research Centre|
|Date Deposited:||08 Sep 2009 09:58|
|Last Modified:||19 Sep 2010 05:24|
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