Ferroelectric SbSI-Crystals Exhibiting Dual Electrical Nature

Abstract

We report synthesis and characterization of rod shaped SbSI crystals that exhibit semiconducting and metallic properties as well. The shiny crystals of SbSI were synthesized using powders of antimony, sulphur and iodine as the precursors by an indigenously developed chemical vapour deposition (CVD) technique. The as-obtained crystals were characterized through the SEM, EDS, XRD, micro Raman analysis and electrical conductivity techniques. The crystal composition was determined by an EDS technique and is found to be very nearly stoichiometric. Surface morphology by SEM showed needle shaped crystallites of 50-100 µm in size. The X-ray diffraction studies gave crystalline nature with a good match of interplaner distances (d), reflected intensities (I/Imax) and lattice constants revealing orthorhombic phase structure of SbSI. Micro- Raman analysis showed characteristics peaks at 12 cm-1, 70 cm-1, 81 cm-1, 90 cm-1, 118 cm-1, 151 cm-1, 226 cm-1 and 331 cm-1 confirming the crystal to be SbSI. SbSI showed semiconducting behaviour in the range of temperature from 300K to 525K whereas it behaves as Metallic in the 300K to 4K temperature range.