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Alloying aluminum nitride with molybdenum could significantly enhance its electromechanical coupling constant.
- Source :
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Journal of Alloys & Compounds . Dec2023, Vol. 968, pN.PAG-N.PAG. 1p. - Publication Year :
- 2023
-
Abstract
- Aluminum nitride (AlN) has been widely used in bandpass filters for wireless communication applications, but its low electromechanical coupling factor (k t 2 ) limits the bandwidth of the filter based on it. In this work, AlN alloys incorporated with various transition metals are theoretically studied, and Mo-alloy AlN (Mo x Al 1−x N) is predicted to be more prominent in improving k t 2 . Furthermore, the influence of Hubbard U correction on the k t 2 of Mo x Al 1−x N is discussed, and the correction is found to show a crucial role at a high x. The magnitude of k t 2 is more correlated with the piezoelectric stress constant e 33 , and both of them depend on the distribution of Mo atoms. The contribution of each atom to piezoelectric performance is described by an effective displacement-response internal-strain parameter Γ 33 in this work, which is generally proportional to internal parameter u and response of u to applied strain along the z -axis. The increase of k t 2 is ascribed to the Mo-induced larger u and Γ 33 , but the Mo dimer and line along the z-axis weaken the increase mechanism. To obtain a high k t 2 , it is better to alloy Mo atoms into more sublayers of AlN and with fewer Mo dimers and lines along the z -axis. The behavior that the Mo atoms distributed evenly in the xy plane is also beneficial. A high k t 2 of 37.8% is predicted in a special quasirandom configuration of Mo 0.167 Al 0.833 N, which might be the highest value reported to date for the AlN alloys. [Display omitted] • Mo-alloy AlN outperforms other alloys in enhancing the k t 2 of AlN. • A high k t 2 of 6.87 times that of pure AlN is predicted. • The magnitude of k t 2 depends on the distribution of Mo atoms in Mo x Al 1−x N. • Γ 33 is used for the first time to explain the contribution of each atom to k t 2 . [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 09258388
- Volume :
- 968
- Database :
- Academic Search Index
- Journal :
- Journal of Alloys & Compounds
- Publication Type :
- Academic Journal
- Accession number :
- 172809186
- Full Text :
- https://doi.org/10.1016/j.jallcom.2023.171857