Echo spectroscopy of TLS of multiwell adiabatic potential for Pr3+ activator centers in Y2SiO5

Based on the investigation of the temperature dependence of the two-pulse phonon echo amplitude on the 3H4 3Po resonant optical transition of the Pr3+ doped ions in the Y2SiO5 crystal, unusual for crystals, low-temperature mechanisms of Pr3+ spectral line broadening caused by the interaction of doped ions with TLS have been found. The constants characterizing the interaction of the doped Pr3+ ions with phonons and TLS have been determined.