Title :
SAW-properties of langasite at high temperatures: Measurement and analysis
Author :
Shrena, Ismail ; Eisele, David ; Mayer, Elena ; Reindl, Leonhard Michael ; Bardong, Jochen ; Schmitt, Martin
Author_Institution :
Dept. of Microsyst. Eng., Univ. of Freiburg, Freiburg, Germany
Abstract :
The measurement range of temperature using SAW-devices is depending on the substrate material used in the measurements. This dependence is related to the temperature point, where the substrate loses its piezoelectric properties. This occurs by the SAW-materials such as quartz and lithium niobate at about 570°C or 350°C, respectively. The piezoelectric material langasite (La3Ga5SiO14) has a thermodynamically stable phase and do not lose its piezoelectric properties up to its melting point at about 1470 °C and can be used for SAW devices at high temperatures. This paper presents the measurements of acoustical parameters of langasite up to 750°C. Langasite is used as substrate in the measurements with Euler angles (0°, 138.5°, 26.6°) and two different platinum (Pt) layer heights (45 nm and 75 nm) top of a zirconium (Zr) adhesion layer (4 nm). The investigated acoustic properties of langasite are group and phase velocity, propagation loss, and electromechanical coupling coefficient as functions of temperature. The measured data is analyzed using a special signal processing algorithm to obtain these acoustic properties of the Langasite.
Keywords :
adhesion; gallium compounds; interdigital transducers; lanthanum compounds; melting point; piezoelectric materials; piezoelectricity; platinum; surface acoustic wave transducers; thermal stability; zirconium; Euler angles; La3Ga5SiO14; La3Ga5SiO14-Zr-Pt; SAW-devices; acoustical parameters; electromechanical coupling coefficient; interdigital transducers; langasite; lithium niobate; melting point; phase velocity; piezoelectric material; platinum layer; propagation loss; quartz; signal processing algorithm; size 4 nm; size 45 nm; size 75 nm; substrate material; temperature 750 degC; temperature measurement; thermodynamic stability; zirconium adhesion layer; Acoustic measurements; Goniometers; Lithium niobate; Piezoelectric devices; Piezoelectric materials; Surface acoustic wave devices; Temperature dependence; Temperature distribution; Temperature measurement; Zirconium; Acoustical parameters; SAW; Substrate; high temperature properties; langasite;
Conference_Titel :
Signals, Circuits and Systems (SCS), 2009 3rd International Conference on
Conference_Location :
Medenine
Print_ISBN :
978-1-4244-4397-0
Electronic_ISBN :
978-1-4244-4398-7
DOI :
10.1109/ICSCS.2009.5414173
