Modeling the temperature sensitivity of STW propagation on various piezoelectric substrates with help of Lagrangian effective material constants

In this paper, the boundary conditions and the geometry used in the description of the whole problem are prescribed only at a reference known value of temperature. In the particular case of STW propagation that means that the writing of the boundary conditions must not take into account the influence of temperature on the surface profile. As far as the thermal bias can be assumed stress-free, it is easy to expand all computations up to the third order in terms of temperature, which is very useful to accurately optimize STW resonators or resonant sensing elements used in compensated cuts for a wide range of precision applications. Some results are now proposed for the thermal sensitivity of the propagation speed of STW onto LGS and GaPO₄ substrates