S. Riegel, R. Wengenmayr, et al.
Physical Review Letters
Ultrasonic velocity and attenuation data are presented at T < 1 K for pure KTaO3 and for KTaO3 where X = Na and Li. Evidence is obtained for coherent tunnelling of Na ions within a correlation volume containing many impurities through barriers with distributed height and asymmetry parameters. Tunnelling is correlated with dipole-glass formation. No evidence of tunnelling is found in KTaO3 and KTaO3
S. Riegel, R. Wengenmayr, et al.
Physical Review Letters
U. Höchli
Physical Review Letters
U. Höchli, K. Knorr, et al.
Advances in Physics
J. Joffrin, U. Höchli, et al.
Physica B: Physics of Condensed Matter