DocumentCode :
2476519
Title :
P1F-4 Revisiting LGT Dielectric Constants and Temperature Coefficients Up to 120°C
Author :
Davulis, Peter M. ; Sturtevant, Blake T. ; Duy, Stephanie L. ; Da Cunha, Mauricio Pereira
Author_Institution :
Univ. of Maine, Orono
fYear :
2007
fDate :
28-31 Oct. 2007
Firstpage :
1397
Lastpage :
1400
Abstract :
Langatate (LGT) has been grown and characterized more intensively in the past decade and the reported acoustic wave properties of this relatively recent crystal have shown significant variations among different groups. Yet to be determined is how much of this dissimilarity is attributable to variations in the growth process or to different measurement techniques. For the dielectric permittivity, in particular, previously published values of epsivS 11/epsiv0 differ from each other by as much as 33% while those of epsivS 33/epsiv0 differ by up to 25% at room temperature. In this work, the dielectric constants of LGT are determined by measurements made from room temperature (25degC) up to 120degC. The permittivity was extracted from capacitance measurements using a precision LCR meter and computer controlled oven. LGT plates oriented along the X, Y, and Z crystalline axes were cut, ground, and polished to an optical finish at the University of Maine´s Microwave Acoustic Lab facilities. The capacitor electrodes were deposited using an aerosol spray method chosen for ease of fabrication and to allow for multiple uses of each of the LGT sample. The measured relative dielectric constants reported in this work are: epsivS 11/epsiv0 is 17.69 +/- 0.30 and epsivS 33/epsiv0 is 70.73 +/- 1.24, which are 11.5% and 7.3% lower then an average of previously published values. The paper discusses the data provided and the associated uncertainties.
Keywords :
bulk acoustic wave devices; lanthanum compounds; permittivity; piezoelectric materials; spray coating techniques; La3Ga5.5Ta0.5O14; acoustic wave properties; aerosol spray method; capacitance measurements; capacitor electrodes; dielectric constants; langatate; precision LCR meter; temperature 25 C to 120 C; temperature coefficients; Acoustic waves; Capacitance measurement; Capacitors; Crystallization; Dielectric constant; Dielectric measurements; Land surface temperature; Measurement techniques; Microwave ovens; Permittivity measurement;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium, 2007. IEEE
Conference_Location :
New York, NY
ISSN :
1051-0117
Print_ISBN :
978-1-4244-1384-3
Electronic_ISBN :
1051-0117
Type :
conf
DOI :
10.1109/ULTSYM.2007.351
Filename :
4409924
Link To Document :
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