Effects of high pressure on the electrical resistivity and dielectric properties of nanocrystalline SnO(2)

The electrical transport and structural properties of tin oxide nanoparticles under compression have been studied by in situ impedance measurements and synchrotron X-ray diffraction (XRD) up to 27.9 GPa. It was found that the conduction of SnO(2) can be improved significantly with compression. Abnormal variations in resistivity, relaxation frequency, and relative permittivity were observed at approximately 12.3 and 25.0 GPa, which can be attributed to pressure-induced tetragonal- orthorhombic-cubic structural transitions. The dielectric properties of the SnO(2) nanoparticles were found to be a function of pressure, and the dielectric response was dependent on frequency and pressure. The dielectric constant and loss tangent decreased with increasing frequency. Relaxation-type dielectric behaviour dominated at low frequencies. Whereas, modulus spectra indicated that charge carrier short-range motion dominated at high frequencies.