High-Temperature Electromechanical Characterization of AlN Single Crystals
Hexagonal AlN is a non-ferroelectric material and does not have any phase transition up to its melting point (>2000°C), which indicates the potential use of AlN for high-temperature sensing. In this work, the elastic, dielectric, and piezoelectric constants of AlN single crystals were investigate...
| Veröffentlicht in: | IEEE transactions on ultrasonics, ferroelectrics, and frequency control. - 1986. - 62(2015), 10 vom: 07. Okt., Seite 1880-7 |
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| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2015
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| Zugriff auf das übergeordnete Werk: | IEEE transactions on ultrasonics, ferroelectrics, and frequency control |
| Schlagworte: | Journal Article |
| Zusammenfassung: | Hexagonal AlN is a non-ferroelectric material and does not have any phase transition up to its melting point (>2000°C), which indicates the potential use of AlN for high-temperature sensing. In this work, the elastic, dielectric, and piezoelectric constants of AlN single crystals were investigated at elevated temperatures up to 1000°C by the resonance method. We used resonators of five different modes to obtain a complete set of material constants of AlN single crystals. The electrical resistivity of AlN at elevated temperature (1000°C) was found to be greater than 5 × 10(10) Ω · cm. The resonance frequency of the resonators, which was mainly determined by the elastic compliances, decreased linearly with increasing temperature, and was characterized by a relatively low temperature coefficient of frequency, in the range of -20 to -36 ppm/°C. For all the investigated resonator modes, the elastic constants and the electromechanical coupling factors exhibited excellent temperature stability, with small variations over the full temperature range, <11.2% and <17%, respectively. Of particular significance is that due to the pyroelectricity of AlN, both the dielectric and the piezoelectric constants had high thermal resistivity even at extreme high temperature (1000°C). Therefore, high electrical resistivity, temperature independence of electromechanical properties, as well as high thermal resistivity of the elastic, dielectric, and piezoelectric properties, suggest that AlN single crystals are a promising candidate for high-temperature piezoelectric sensing applications |
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| Beschreibung: | Date Completed 13.01.2016 Date Revised 18.09.2019 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1525-8955 |