Sign inversion of the rotatory power and topology of the surface of gyration of αNiSO4·6H2O

The sign inversion point of the rotatory power of the gyrotropic crystals α-NiSO4·6H2O (λl=503 nm at 300 K) has been established. The topology of the gyration surface varies greatly in the vicinity of λl. We have demonstrated the possibility of using this method of spectrophotometric polarimetry for precise monitoring of the mounting of a gyrotropic crystal in the system “polarizer-crystal-analyzer.”