Correlation between structural change and electrical transport properties of Fe-doped chrysotile nanotubes under high pressure

摘要

Fe3+ doped chrysotile nanotubes (NTs) have been synthesized under controlled hydrothermal conditions, and have been characteristic of layered-walls and room-temperature ferromagnetism. High-pressure in situ impedance spectra and synchrotron XRD measurements are performed on Fe-doped chrysotile NTs to reveal the electrical transport and structural properties under compression. Sample resistance (R-sum) was found to increase with the pressure elevation, accompanying the step decrease in the grain boundary relaxation frequency (f(gb)), which reflects the bandgap broadening and dipoles polarization weakening due to the application of pressure. Furthermore, it is found that both R-sum and f(gb) change their pressure dependences at similar to 5.0 GPa, which is attributed to the nonlinear compressibility of c-axis and even the underlying lattice distortion of monoclinic structure obtained in the XRD observations.