Berlin 2005 – wissenschaftliches Programm
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AK: Akustik
AK 2: Hochfrequenzakustik - akustische Oberfl
ächenwellen (Sitzungsorganisation: Eduard Chilla, Teltow)
AK 2.3: Hauptvortrag
Freitag, 4. März 2005, 15:00–15:30, TU EB222
Interface acoustic waves in piezoelectric crystals — •Alexander Darinskii1 and Manfred Weihnacht2 — 1Institute of Crystallography, Russian Academy of Sciences, Leninskii pr. 59, Moscow 119333, Russia — 2Leibniz Institute for Solid State and Materials Research Dresden, P.O. 270016, D-01171 Dresden, Germany
A theoretical study has been made of interface acoustic waves (IAW) propagating in piezoelectric structures of arbitrary symmetry. The interfaces of four types have been considered. 1) Infinitesimally thin metallic layer inserted into homogeneous piezoelectric crystal of arbitrary symmetry. 2) Rigidly bonded crystals whose piezoelectric moduli differ by sign while the other material constants are identical. 3) Perfect sliding contact between identical media. 4) Dielectric gap between two identical piezoelectric. IAWs do not exist obligatory in these structures. We prove the theorems concerning the permissible number and existence conditions for purely localized (non-leaky) and leaky IAWs. We have also analyzed specific resonance singularities of the reflection coefficients for bulk waves; these singularities appear for the angles of incidence corresponding to the excitation of leaky IAW. The conditions for the occurrence of the resonance total reflection have been established. The numerical computations for LiNbO3 and LiTaO3 illustrate general conclusions.