Electrochemical test station pot gal 30v 2a

In situ electrochemical measurements during PLD deposition (i-PLD) were conducted with an Alpha-A High Performance Frequency Analyzer equipped with an Electrochemical Test Station POT/GAL 30V/2A setup (both Novocontrol Technologies, Germany). For i-PLD measurements, a sample was placed on the PLD heater and covered with a corundum mask (cutout 0.45 × 0.45 cm²) to prevent short circuiting of the working electrode and counter electrode via the edges of the sample during the subsequent film deposition. The working electrode was brought into contact with a PtIr-needle and the counter electrode via platinum paste brushed onto the heater. A sketch of the measurement setup can be found in Fig. 1.
Impedance measurements were typically conducted in a frequency range from 10⁶ to 10⁻¹ Hz (if needed for resolving the electrode feature, the frequency range was extended to 10⁻² Hz), with an AC amplitude of 10 mV root-mean-square, and a resolution of 5 or 10 points per frequency decade. In many cases, oxygen partial pressure and temperature were kept at 600 °C and 0.04 mbar O₂ for deposition; in some cases pressure and temperature were varied for a more detailed impedance characterisation.

Measurements
were performed by placing the samples in a closed fused silica apparatus
and heating them in a tube furnace to temperatures between 460 and
608 °C. The temperature was measured with a type S thermocouple,
which was positioned within 1 cm distance to the sample. Electrical
contact of the counter electrodes was realized by placing the samples
on a platinum mesh. The (working) microelectrodes were contacted by
means of platinum–rhodium needles using a microscope camera.
Impedance measurements with DC bias voltages from 0 to 440 mV
were carried out using an Alpha-A High Performance Frequency Analyzer
with an Electrochemical Test Station POT/GAL 30 V/2 A
(both: Novocontrol Technologies GmbH & Co. KG, Germany). An alternating
root-mean-square voltage of 10 mV was employed, and impedance
spectra were measured in the frequency range of 10⁶ to
10^–2 Hz with 5 data points per decade. DC
voltages and currents were also measured with the Electrochemical
Test Station. All measurements were performed in synthetic air (99.999%,
Messer Austria GmbH, Austria).

i-PLD was performed
with a custom-made setup inside the PLD chamber.^{40 (link)} The bottom Ti/Pt grid was contacted with a brushed Pt electrode
on the heating stage, and the top grid was contacted with a Pt/Ir
needle. The temperature during i-PLD was controlled by evaluating
the ohmic offset in an across-plane impedance measurement. This offset
resistance includes contributions from wiring and grid resistances,
which were determined beforehand, as well as from thermally activated
ionic conduction through the electrolyte substrates. With the known
conductivity–temperature relationships for YSZ and LSGM,^{38 (link),41 (link)} this technique allows for a very exact temperature measurement during
the PLD process. Impedance measurements were conducted with an Alpha-A
High Performance Frequency Analyzer and Electrochemical Test Station
POT/GAL 30 V/2A setup by Novocontrol Technologies in the frequency
regime from 10⁶ to 10^–1 Hz with an alternating-current
(ac) voltage of 20 mV root mean square (RMS). Ex situ measurements in synthetic air (5.0 purity, Messer, Austria) were
performed with the same setup by Novocontrol Technologies and a measurement
setup in a tube furnace. The temperature was measured with a type
S thermocouple, positioned 1 cm next to the sample.