Ion conduction in single crystals of the hollandite-type one-dimensional superionic conductor NaxCrxTi8−xO16 (x=1.7)

Ion conduction of Na+ ions in single crystals of a one-dimensional superionic conductor, Na–Cr–priderites NaxCrxTi8−xO16 (x=1.7), has been studied by an impedance spectroscopy method. In the low-frequency region, a frequency-independent conduction process was observed. The conduction process was thermally activated and the value of the total activation energy was about 0.288 eV. The value of the frequency-independent ion conductivity was about 2×10−5 S/cm at room temperature and 10−2 S/cm at 200°C.