Authors

W. L. Johnson; S. A. Kim; S. Uda;C. F. Rivenbark

Comments

Authors: contact us about adding a copy of your work at [email protected]

Abbreviated Journal Title

J. Appl. Phys.

Keywords

TEMPERATURE PIEZOELECTRIC MATERIALS; INDUCED FREQUENCY-SHIFTS; INTERNAL-FRICTION; ELECTROMECHANICAL PROPERTIES; ELEVATED-TEMPERATURES; DIELECTRIC-PROPERTIES; DEFECT CHEMISTRY; SINGLE-CRYSTALS; CUT; RESONATORS; KINK MOTION; Physics, Applied

Abstract

Maximization of the quality factors Q of langasite (LGS) and langatate (LGT) is necessary for optimal performance of acoustic resonators of these materials in frequency-control and high-temperature sensing applications. In this report, measurements and least-squares analysis of Q(-1) as a function of ultrasonic frequency and temperature of undoped LGS (100 K to 750 K) and LGT (300 K to 760 K) reveal a superposition of physical effects, including point-defect relaxations and intrinsic phonon-phonon loss. In LGS, these effects are superimposed on a large temperature-dependent background with weak frequency dependence that is interpreted as arising from a relaxation process with a distribution of activation energies. This distributed relaxation is suggested to be a result of anelastic kink migration. No evidence for a significant background of this form is found in the LGT specimen, consistent with the lower measured dislocation etch-pit density of this crystal. The analysis of the dependence of Q(-1) of LGT on frequency and temperature indicates that, at near-ambient temperatures, the damping in this specimen is close to the intrinsic limit determined by phonon-phonon interactions. Piezoelectric/carrier relaxation, which must occur at sufficiently elevated temperatures, is found not to be a significant contribution to Q(-1), relative to defect-related contributions, in either LGS or LGT in the measured range of temperatures.

Journal Title

Journal of Applied Physics

Volume

110

Issue/Number

12

Publication Date

1-1-2011

Document Type

Article

Language

English

First Page

12

WOS Identifier

WOS:000298639800042

ISSN

0021-8979

Download

Share

COinS
 

Accessibility Statement

This item was created or digitized prior to April 24, 2027, or is a reproduction of legacy media created before that date. It is preserved in its original, unmodified state specifically for research, reference, or historical recordkeeping. In accordance with the ADA Title II Final Rule, the University Libraries provides accessible versions of archival materials upon request. To request an accommodation for this item, please submit an accessibility request form.