Synthesis of orthorhombic Sb2O3 branched rods by a vapor–solid approach

Abstract

In this work, Sb2O3 nanorods, microrods and crystals were synthesized by a carbothermal reduction driven vapor–solid(VS) process. Aiming to provide data on the structure of these samples XRD, FEG-SEM and Raman spectroscopy were used. As result, we found that samples collected at the hottest growth zone (630-760 °C) are composed by microrods showing branched morphology (nanometric branches) and orthorhombic phase of Sb2O3. A cubic Sb2O3 phase was detected in samples collected at the intermediate growth zone (440-510 °C) and at the coldest growth zone (180-250 °C). The examination of Raman selection rules in both orthorhombic and cubic samples revealed solid evidences of the presence of native defects, which we believe to be oxygen vacancies. Symmetric Schottky barriers were constructed to orthorhombic Sb2O3samples and the main electrical features of the devices such as barriers height ΦB=0.44eV and ideality factor n=1.03 for Au/Ti contacts were found. The temperature-dependent resistance measurements have confirmed for the first time a semiconductor-like behavior in orthorhombic Sb2O3 structures.