NISCAIR Online Periodicals Repository

Research Journals >
Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.47 [2009] >
IJPAP Vol.47(02) [February 2009] >

Title: Temperature dependence of microwave loss in antiferroelectric squaric acid crystal
Authors: Upadhyay, Trilok Chandra
Keywords: Antiferroelectrics
Anharmonic interactions
Loss tangent
Issue Date: Feb-2009
Publisher: CSIR
Abstract: A model of pseudospin for layers 1 and 2 of squaric acid (SQA) crystal proposed by Li and Qin, Ferroelectrics, 82 (1988), 69 has been modified to include pseudospin-phonon interaction and cubic and quartic phonon anharmonic interactions. With the help of double-time temperature dependent Green's function method and modified Hamiltonian, expressions for antiferroelectric soft mode frequency, dielectric constant and loss have been evaluated. By fitting model values of physical quantities in the theoretical expressions, temperature dependences of soft mode frequency and loss have been calculated. In the microwave frequency range, an increase in frequency is followed by increase in loss. The loss decreases with increase in temperature for SQA crystal in its paraelectric phase. This shows Curie-Weiss behaviour of the dielectric tangent loss. Theoretical results are compared with experimental results of Muser [Proc. 6th Int'l Meeting on Ferroelectricity, Kobe (1985)], Maier et al. [Phys Status Solidi (b) 89, (1978)], and Samara and Semmingsen [J Chem Phys 71 (3) (1979) 1401] which show a good agreement.
Page(s): 119-124
ISSN: 0019-5596
Source:IJPAP Vol.47(02) [February 2009]

Files in This Item:

File Description SizeFormat
IJPAP 47(2) 119-124.pdf143.19 kBAdobe PDFView/Open
 Current Page Visits: 69 
Recommend this item


Online Submission of Articles |  NISCAIR Website |  National Knowledge Resources Consortium |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2015 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 162361 since 01-Sep-2015  Last updated on 21-Jun-2016Webmaster: