부산대학교 도서관

Three different photomagnetic effects caused by ultraviolet light in paramagnetic crystals based on molecules of spiropyrans (Sp) Sp3Cr(C2O4)3 and SpI have been revealed and separated: (1) in the high-temperature range (30–300 K), the photomagnetic effect in Sp3Cr(C2O4)3 is determined by the charge transfer between chromium ions and spiropyran molecules; (2) in the low-temperature range (2 K), the photomagnetic effect in Sp3Cr(C2O4)3 is due to the photoisomerization of spiropyran molecules, the change in the crystal field, and the splitting of the levels of Cr3+ ions in zero field; and (3) in the temperature range 2–20 K, the generation of radiation-induced paramagnetic defects contributes to the magnetic moment of the organic sublattice Sp+.