NISCAIR Online Periodicals Repository

NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR)  >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.47 [2009] >
IJPAP Vol.47(01) [January 2009] >


Title: Temperature dependence of microwave loss in ADP-type crystals
Authors: Upadhyay, Trilok Chandra
Keywords: Antiferroelectrics
Anharmonic interactions
Dielectric
Loss tangent
Issue Date: Jan-2009
Publisher: CSIR
Abstract: By using four sublattice pseudospin lattice coupled mode model along with third and fourth-order phonon anharmonic interaction terms for ADP-type crystals, expressions for shift, width, renormalized soft mode frequency, dielectric constant and loss have been evaluated. The method of double-time thermal Green's function has been used for calculation. Fitting the values of model parameters in expressions, the 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 ADP crystal in its paraelectric phase. This shows Curie-Weiss behaviour of the dielectric tangent loss. Theoretical results are compared with experimental results of Nagamiya [Progr Theor Phys, 7 (1952) 275] and Busch, Helv Phys Acta, 11 (1938) 269]. A good agreement has been found.
Page(s): 66-72
ISSN: 0019-5596
Source:IJPAP Vol.47(01) [January 2009]

Files in This Item:

File Description SizeFormat
IJPAP 47(1) 66-72.pdf307.71 kBAdobe PDFView/Open
 Current Page Visits: 568 
Recommend this item

 

National Knowledge Resources Consortium |  NISCAIR Website |  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 © 2012 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: 549606 since 06-Feb-2009  Last updated on 12-Jul-2014Webmaster: nopr@niscair.res.in