Crystal growth, structure, morphology, optical, thermal and electrical studies of dysprosium chloride–thiourea semi-organic complex crystal

In the present investigations, attempts were made to grow semi-organic composition of thiourea mixed with dysprosium chloride (abbreviated as TuDyCl). The growth of this semi-organic composition is being achieved by room-temperature slow evaporation technique. These were then characterised by using techniques like powder X-ray diffraction, scanning electron microscope (SEM), UV–Vis analysis, Fourier transformation infrared spectroscopy (FTIR), thermal and electrical studies. The composition crystallises in an orthorhombic crystal system having the space group P nma . The crystallinity and purity were tested by powder X-ray diffraction. Structural morphology, as analysed using SEM, suggests the formation of microcrystals with certain inclusions. Optical spectra suggest a good optical transmission in the entire visible region and the lower cut-off wavelength at 278 nm. The absence of absorption of light in the visible region makes the crystals suitable for optoelectronic applications. The band gap comes out to be 4.24 eV. Other parameters like extinction coefficient, refractive index, optical and electrical conductivity were also analysed. Identification of the expected functional groups and various modes of vibrations present in the grown crystals was carried out by FTIR. Thermal effects, such as dehydration, melting and decomposition mechanism, were observed using thermoanalysis techniques. Electrical performance was tested to understand the electrical response of the materials with externally applied fields as a function of temperature and frequency.