  In this short review, some bulk threshold phenomena of the unconventional
superconductivity in the strontium ruthenate compound (Sr2RuO4) are mentioned.
Particularly, in Sr2RuO4, the Ehrenfest relations, the velocity propagation of
the elastic field modes, and the ultrasound attenuation find a common point to
study elastic anisotropic lattice field effects at the transition temperature
(Tc) between the normal and the superconducting state. Ehrenfest relations are
suitable for establishing a phase diagram of the Tc point according to symmetry
consideration of the electrons pairs in unconventional superconductors. Further
studies in this direction could turn into a new role for the spin polarization
of the transverse phonon field and its interaction with the conduction
electrons in anisotropic crystals with several conducting/superconducting bands
such as Sr2RuO4.
