Temperature evolution of the intra-ion absorption spectra of (NH2(C2H5)2)2CoCl4 crystals in the region of their phase transitions. (3rd April 2019)

• Record Type: Journal Article
• Authors: Kapustianyk, V.; Semak, S.; Panasyuk, M.; Rudko, M.; Rudyk, V.
• Is Part Of: Phase transitions. Volume 92:Number 4(2019)
• Page Start: 396
• Page End: 405
• Publication Date: 2019-04-03
• Subjects: Absorption band -- crystal field -- phase transitions -- absorption coefficient -- electronic transition -- ferroic materials; 03.75.Hh -- 61.50.−f -- 61.50.Ah -- 78.40.−q -- 78.20.−e; Phase transformations (Statistical physics) -- Periodicals; 530.47405
• DOI: 10.1080/01411594.2019.1591407
• Languages: English
• ISSNs: 0141-1594

Abstract

ABSTRACT: On the basis of spectroscopic studies of (NH2 (C2 H5 )2 )2 CoCl4 crystals, the absorption bands corresponding to the internal electronic transitions in the Co 2+ ion were identified. The values of the crystal field and Racah parameters were calculated. The temperature evolution of the absorption spectra of (NH2 (C2 H5 )2 )2 CoCl4 crystals reveals the anomalies of their parameters at the points of phase transitions. The corresponding changes of the absorption spectra were discussed in terms of distortion of the metal-halogen complex. The temperature dependences of the absorption spectra of (NH2 (C2 H5 )2 )2 CoCl4 crystals confirm the presence of the thermochromic phase transitions at 255 and 330 K.