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.
Mit Hilfe der Elektronen-Spin-Echo-Methode wurden rontgenbestrahlte ferroelektrische Rochelle-Salz-, Dikalzium-Strontium-Propionat- und TGS-Einkristalle untersucht. Die gemessenen Spin–Gitter-Relaxationszeiten T1 zeigen charakteristische Anomalien bei Temperaturen unmittelbar unter dem Curie-Punkt. Aus der Untersuchung der Winkelabhangigkeit von T1 in Rochelle-Salz folgt, das die Relaxationsrate nicht durch Drehschwingungen des Molekuls bestimmt wird, sondern durch Gitterschwingungen, die eine Modulation der Spin-Bahn-Kopplung verursachen.
[1]
L. Dalton,et al.
Electron spin-lattice relaxation in molecular crystals: S = 12
,
1972
.
[2]
W. Berlinger,et al.
Fluctuations and Correlations in SrTiO3 for T>=Tc
,
1972
.
[3]
I. Suzuki,et al.
Electron Spin Resonance of Gamma-Irradiated Rochelle Salt Single Crystal. I. Analysis of Center No. 2
,
1967
.
[4]
W. Moulton,et al.
Paramagnetic Resonance of X‐Irradiated Single Crystals of Rochelle Salt
,
1961
.
[5]
S. Hoshino,et al.
CRYSTAL STRUCTURE OF THE FERROELECTRIC PHASE OF (GLYCINE)$sub 3$/CENTER DOT/ H$sub 2$SO$sub 4$
,
1959
.