Platinum and palladium high-temperature transducers on langasite.
IEEE Trans Ultrason Ferroelectr Freq Control. 2005 Apr; 52(4):545-9.IT

Abstract

There is a pressing need for the fabrication of surface acoustic wave (SAW) devices capable of operating in harsh environments, at elevated temperature and pressure, or under high-power conditions. These SAW devices operate as frequency-control elements, signal-processing filters, and pressure, temperature, and gas sensors. Applications include gas and oil wells, high-power duplexers in communication systems, and automobile and aerospace combustion engines. Under these high-temperature and power-operating conditions, which can reach several hundred degrees Centigrade, the typically fabricated aluminum (A1) thin film interdigital transducer (IDT) fails due to electro and stress migration. This work reports on high temperature SAW transducers that have been designed, fabricated, and tested on langasite (LGS) piezoelectric substrates. Platinum (Pt) and palladium (Pd) (melting points at 1769 degrees C and 1554.9 degrees C, respectively) have been used as thin metallic films for the SAW IDTs fabricated. Zirconium (Zr) was originally used as an adhesion layer on the fabricated SAW transducers to avoid migration into the Pt or Pd metallic films. The piezoelectric LGS crystal, used as the substrate upon which the SAW devices were fabricated, does not exhibit any phase transition up to its melting point at 1470 degrees C. A radio frequency (RF) test and characterization system capable of withstanding 1000 degrees C has been designed and constructed. The LGS SAW devices with Pt and Pd electrodes and the test system have been exposed to temperatures in the range of 250 degrees C to 750 degrees C over periods up to 6 weeks, with the SAW devices showing a reduced degradation better than 7 dB in the magnitude of transmission coefficient, /S21/, with respect to room temperature. These results qualify the Pt and Pd LGS SAW IDTs fabricated for the above listed modern applications in harsh environments.

Authors+Show Affiliations

Thiele JA

Department of Electrical and Computer Engineering, Laboratory for Surface Science and Technology, University of Maine, Orono, Maine, USA.

da Cunha MP

No affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

16060501

Citation

Thiele, Jeremy A., and Mauricio Pereira da Cunha. "Platinum and Palladium High-temperature Transducers On Langasite." IEEE Transactions On Ultrasonics, Ferroelectrics, and Frequency Control, vol. 52, no. 4, 2005, pp. 545-9.

Thiele JA, da Cunha MP. Platinum and palladium high-temperature transducers on langasite. IEEE Trans Ultrason Ferroelectr Freq Control. 2005;52(4):545-9.

Thiele, J. A., & da Cunha, M. P. (2005). Platinum and palladium high-temperature transducers on langasite. IEEE Transactions On Ultrasonics, Ferroelectrics, and Frequency Control, 52(4), 545-9.

Thiele JA, da Cunha MP. Platinum and Palladium High-temperature Transducers On Langasite. IEEE Trans Ultrason Ferroelectr Freq Control. 2005;52(4):545-9. PubMed PMID: 16060501.

* Article titles in AMA citation format should be in sentence-case

TY - JOUR T1 - Platinum and palladium high-temperature transducers on langasite. AU - Thiele,Jeremy A, AU - da Cunha,Mauricio Pereira, PY - 2005/8/3/pubmed PY - 2005/8/3/medline PY - 2005/8/3/entrez SP - 545 EP - 9 JF - IEEE transactions on ultrasonics, ferroelectrics, and frequency control JO - IEEE Trans Ultrason Ferroelectr Freq Control VL - 52 IS - 4 N2 - There is a pressing need for the fabrication of surface acoustic wave (SAW) devices capable of operating in harsh environments, at elevated temperature and pressure, or under high-power conditions. These SAW devices operate as frequency-control elements, signal-processing filters, and pressure, temperature, and gas sensors. Applications include gas and oil wells, high-power duplexers in communication systems, and automobile and aerospace combustion engines. Under these high-temperature and power-operating conditions, which can reach several hundred degrees Centigrade, the typically fabricated aluminum (A1) thin film interdigital transducer (IDT) fails due to electro and stress migration. This work reports on high temperature SAW transducers that have been designed, fabricated, and tested on langasite (LGS) piezoelectric substrates. Platinum (Pt) and palladium (Pd) (melting points at 1769 degrees C and 1554.9 degrees C, respectively) have been used as thin metallic films for the SAW IDTs fabricated. Zirconium (Zr) was originally used as an adhesion layer on the fabricated SAW transducers to avoid migration into the Pt or Pd metallic films. The piezoelectric LGS crystal, used as the substrate upon which the SAW devices were fabricated, does not exhibit any phase transition up to its melting point at 1470 degrees C. A radio frequency (RF) test and characterization system capable of withstanding 1000 degrees C has been designed and constructed. The LGS SAW devices with Pt and Pd electrodes and the test system have been exposed to temperatures in the range of 250 degrees C to 750 degrees C over periods up to 6 weeks, with the SAW devices showing a reduced degradation better than 7 dB in the magnitude of transmission coefficient, /S21/, with respect to room temperature. These results qualify the Pt and Pd LGS SAW IDTs fabricated for the above listed modern applications in harsh environments. SN - 0885-3010 UR - https://www.unboundmedicine.com/medline/citation/16060501/Platinum_and_palladium_high_temperature_transducers_on_langasite_ DB - PRIME DP - Unbound Medicine ER -

Tags

Platinum and palladium high-temperature transducers on langasite.IEEE Trans Ultrason Ferroelectr Freq Control. 2005 Apr; 52(4):545-9.IT