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CN-122016943-A - Perovskite oxide film proton conduction in-situ detection device and method based on resistance real-time monitoring

CN122016943ACN 122016943 ACN122016943 ACN 122016943ACN-122016943-A

Abstract

The invention discloses a perovskite oxide film proton conduction in-situ detection device and method based on resistance real-time monitoring, and belongs to the technical field of functional materials and electrochemical sensing. The invention adopts pulse laser to deposit on SrTiO3 monocrystal substrate to epitaxially grow SrCoO2.5 film, prepares Pt electrode on the film surface to form resistance measuring structure, places the sample in a sealed cavity capable of independently and accurately controlling temperature, humidity and atmosphere, introduces water vapor with controllable partial pressure, utilizes a high-precision resistance meter to continuously, real-time and high-frequency collect film resistance, and synchronously records the changes of temperature, humidity and gas partial pressure along with time. The SrCoO2.5 film generates hydration phase change when meeting water vapor to generate hydration phase SCOH, the resistivity is suddenly reduced by more than four orders of magnitude, and the inverse resistance 1/R is in a linear reduction relation with time. By fitting the linear section of the normalized resistance R0/R (t), the rate constant k can be obtained directly.

Inventors

  • HU SONGBAI
  • HUANG PEIYI
  • CHEN LANG

Assignees

  • 大湾区大学

Dates

Publication Date
20260512
Application Date
20260325

Claims (10)

  1. 1. A perovskite oxide film proton conduction in-situ detection method based on resistance real-time monitoring is characterized by comprising the following steps of (1) adopting a pulse laser deposition technology to epitaxially grow a SrCoO2.5 film on a SrTiO3 monocrystal substrate to form a uniform epitaxial film with the thickness of d, (2) preparing a Pt electrode on the surface of the SrCoO2.5 film by adopting magnetron sputtering to form a resistance measurement electrode pair, (3) placing a prepared sample into a sealed temperature-controlled cavity, independently and accurately controlling the internal temperature, relative humidity and gas atmosphere partial pressure, (4) controlling carrier gas flow through a mass flowmeter, introducing water vapor with preset partial pressure into the cavity by utilizing a water vapor generator to enable the sample to be exposed to a water vapor environment at t=0 moment, (5) adopting a high-precision resistor to continuously and real-time acquire the film resistance under the set temperature, relative humidity and atmosphere conditions, (6) synchronously recording the change curve of the resistance, the relative humidity and the water vapor partial pressure along with time, (7) taking the resistance at t=0 as a reference resistance R0, calculating the normalized resistance R0/R (t), calculating the linear velocity of the resistance at t=0 moment, and calculating the linear velocity of the change along the proton conduction velocity along the time v, and obtaining the reciprocal velocity of the proton conduction constant along the time section, and calculating the reciprocal velocity.
  2. 2. The method of claim 1, wherein the srcoo2.5 film thickness d is 5 nm, 10 nm, 20nm, 30 nm or 50 nm.
  3. 3. The method of claim 1, wherein the sampling frequency of the resistor acquisition is 10 Hz to 100 Hz, and the sampling time interval is not greater than 1 second.
  4. 4. The method of claim 1, wherein the test temperature is 250 ℃ to 350 ℃, the relative humidity is 10% -80%, the total pressure of the cavity is 0.1 MPa to 0.5 MPa, and the partial pressure of oxygen is 0% -5%.
  5. 5. The method of claim 1, wherein the SrCoO2.5 film is prepared at a substrate temperature of 650 ℃, an oxygen partial pressure of 0.1 Pa, and after the deposition, it is annealed at 500 ℃ and an oxygen partial pressure of 10 Pa for 30 minutes.
  6. 6. The method according to claim 1, wherein the criterion for the linear fitting is that the fitting decision coefficient R2 is not less than 0.98.
  7. 7. A proton conduction in-situ detection device for realizing the method of claim 1 is characterized by comprising a substrate seat, a sealed temperature control cavity, a high-precision resistance measurement module, a data synchronous acquisition and processing module, a resistance-time curve linear fitting and a speed constant k and a proton conduction front speed v, wherein the substrate seat is used for fixing a test sample with a SrCoO2.5 film and a Pt electrode, the sealed temperature control cavity is provided with a heating module, a humidity control module, a gas inlet, a gas outlet and a mass flowmeter, the high-precision resistance measurement module is connected with the Pt electrode on the sample and is used for acquiring film resistance in real time, and the data synchronous acquisition and processing module is used for synchronously recording resistance, temperature, humidity and gas partial pressure data and carrying out linear fitting on a resistance-time curve.
  8. 8. The device of claim 7, wherein the sealed temperature-controlled chamber is provided with an optical window for simultaneous in situ characterization of raman spectroscopy, infrared spectroscopy, or X-ray diffraction.
  9. 9. The device of claim 7, wherein the device is equipped with a temperature sensor and a humidity sensor to feed back environmental parameters in the chamber in real time.
  10. 10. The use of the method according to claim 1, characterized by the in-situ, real-time, quantitative characterization of the perovskite oxide proton conduction kinetics of srcoo2.5 and its derivatives.

Description

Perovskite oxide film proton conduction in-situ detection device and method based on resistance real-time monitoring Technical Field The invention relates to the technical field of functional materials and electrochemical sensing, in particular to a device and a method for detecting proton conduction dynamic processes in perovskite oxide films in real time on the basis of resistance real-time monitoring. Background Proton conducting materials are core functional materials in the fields of solid oxide fuel cells, electrolytic cells, gas sensors, hydrogen storage materials and the like. Currently, the dominant characterization methods of proton conduction behavior include isotope labeling-secondary ion mass spectrometry and alternating current impedance spectrometry. The isotope tracing-secondary ion mass spectrometry has complex flow and long test period, can only obtain offline and static ion distribution information, and cannot realize real-time dynamic monitoring. The ac impedance spectroscopy can only reflect steady-state or quasi-steady-state response, and is difficult to capture fast transient processes such as proton implantation, migration, capture, lattice chemical expansion and the like. The prior art has the defects of poor instantaneity, weak in-situ capability, insensitivity to a rapid process, difficulty in realizing continuous monitoring under the conditions of temperature change, humidity change, atmosphere change and the like, and can not meet the requirements of perovskite oxide proton conduction microscopic mechanism research. Therefore, developing a detection method and device capable of resolving proton conduction dynamic process in situ, in real time, with high sensitivity and quantitatively becomes a technical problem to be solved in the field. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a perovskite oxide film proton conduction in-situ detection device and method based on resistance real-time monitoring, which realize second-level dynamic tracking, multi-physical field coupling in-situ test and high-sensitivity quantitative analysis in a proton conduction process and solve the problems that the traditional characterization method is poor in instantaneity, weak in-situ capability and incapable of capturing a rapid dynamic process. Technical proposal (1) The preparation of the film adopts a pulse laser deposition technology to epitaxially grow a SrCoO2.5 film on a SrTiO3 (001) monocrystalline substrate. The deposition conditions were a substrate temperature of 650 ℃, an oxygen partial pressure of 0.1 Pa, a laser wavelength of 248 nm, a pulse energy of 300 mJ, and a frequency of 5 Hz. The film thickness can be controlled to be 5 nm, 10 nm, 20 nm, 30 nm, 50nm. After the deposition, annealing is carried out for 30 minutes under the conditions of 500 ℃ and 10 Pa of oxygen partial pressure, and the epitaxial film with high crystallization quality and high orientation is obtained. (2) The electrode is prepared by depositing a Pt electrode on the surface of the SrCoO2.5 film by magnetron sputtering, and the thickness is 20 nm, so that a two-probe or four-probe measuring structure is formed, the current is ensured to be uniformly distributed, and the measuring precision and stability are improved. (3) The in-situ test environment is constructed, a sample is filled into a sealed temperature-control cavity, the temperature of the cavity is controlled to be 250-350 ℃ independently and accurately, the relative humidity is controlled to be 10-80%, the carrier gas is N2, ar and O2 or mixed gas thereof, the total pressure is 0.1-0.5 MPa, and the oxygen partial pressure is controlled to be 0-5%. The hydration reaction of the film is triggered by rapid steam introduction at time t=0 by a steam generator. (4) The resistor is collected in real time, a high-precision resistor meter is adopted to collect the resistor R (t) continuously at the frequency of 10 Hz-100 Hz, and the temperature, the humidity and the gas partial pressure are recorded synchronously. (5) The data analysis method takes the resistance at the time of t=0 as a reference resistance R0, and calculates normalized resistance R0/R (t). The inverse resistance 1/R decreases linearly with time, satisfying 1/R (t) =1/R0-k, where k is the rate constant, in s-1. Proton conduction transition front velocity v satisfies that v=k and dd is the film thickness. And k is obtained through linear fitting, v can be calculated, and quantitative analysis of proton conduction dynamics is realized. A perovskite oxide film proton conduction in-situ detection device and method based on resistance real-time monitoring, the principle and deduction process are as follows: Let SrCoO2.5 film total thickness be d, width be w, length be L. When exposed to water vapor at time t=0, hydration reactions occur, yielding SCOH (hydrated phase) regions. The geometry is similar to a parallel circuit in that the unconverted SCO region (r