2 research outputs found
Electrical Double Layer at Various Electrode Potentials: A Modification by Vibration
This paper proposes a vibration model
of ions as an improvement over the conventional Gouy–Chapman–Stern
theory, which is used to model the electrical double layer capacitance
and to study the ionic dynamics at electrode/electrolyte interfaces.
Although the Gouy–Chapman–Stern model is successful
for small applied potentials, it fails to explain the observed behavior
at larger potentials, which are becoming increasingly important as
materials with high charge injection capacities are developed. A time-dependent
study on ionic transport indicates that ions vibrate near the electrode
surface in response to the applied electric field. This vibration
allows us to correctly predict the experimentally observed decreasing
differential capacitance at high electrode potential. This new model
elucidates the mechanism behind the ionic dynamics at solid–electrolyte
interfaces, providing useful insight that may be applied to many electrochemical
systems in energy storage, photoelectrochemical cells, and biosensing
Spin–Orbit Interaction in a Two-Dimensional Hole Gas at the Surface of Hydrogenated Diamond
Hydrogenated diamond possesses a
unique surface conductivity as a result of transfer doping by surface
acceptors. Yet, despite being extensively studied for the past two
decades, little is known about the system at low temperature, particularly
whether a two-dimensional hole gas forms at the diamond surface. Here
we report that (100) diamond, when functionalized with hydrogen, supports
a <i>p</i>-type spin-3/2 two-dimensional surface conductivity
with a spin–orbit interaction of 9.74 ± 0.1 meV through
the observation of weak antilocalization effects in magneto-conductivity
measurements at low temperature. Fits to 2D localization theory yield
a spin relaxation length of 30 ± 1 nm and a spin-relaxation time
of ∼0.67 ± 0.02 ps. The existence of a 2D system with
spin orbit coupling at the surface of a wide band gap insulating material
has great potential for future applications in ferromagnet–semiconductor
and superconductor–semiconductor devices