Proton tunneling: a decay channel of the O-H stretch mode in KTaO3.
The vibrational lifetimes of the O-H and O-D stretch modes in the perovskite oxide KTaO3 are measured by pump-probe infrared spectroscopy. Both stretch modes are exceptionally long lived and exhibit a large "reverse" isotope effect, due to a phonon-assisted proton-tunneling process, which involves the O-Ta-O bending motion. The excited-state tunneling rate is found to be 7 orders of magnitude larger than from the ground state in the proton conducting oxide, BaCeO3 [Phys. Rev. B 60, R3713 (1999)].
Spahr
E J
EJ
Department of Applied Science, College of William and Mary, Williamsburg, Virginia 23187, USA.
Wen
L
L
Stavola
M
M
Boatner
L A
LA
Feldman
L C
LC
Tolk
N H
NH
Lüpke
G
G
D003903:Deuterium / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D006860:Hydrogen Bonding; D006878:Hydroxides / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D010087:Oxides / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry*; D011522:Protons; D013635:Tantalum / Q000737:chemistry*
D006878:Hydroxides; D010087:Oxides; D011522:Protons; C516825:potassium tantalate oxide; D013635:Tantalum; D006859:Hydrogen; C031356:hydroxide ion; D003903:Deuterium; D011188:Potassium