Investigations of anisotropy and anomaly of the electron spin relaxation time in ferroelectric crystals by means of the electron spin echo method

X-irradiated ferroelectric single crystals of hydrogen bonded Rochelle salt, dicalcium strontium propionate, and TGS were studied by means of the electron spin echo method. The investigated spin-lattice relaxation time T1 shows characteristic anomalies at temperatures immediately below the Curie point. The study of the angular dependence of T1 in Rochelle salt gives the result, that the relaxation rate is not caused by rotational vibrations of the molecule, but by phonon modulation of the spin-orbit coupling.