Quartz Crystal Microbalance equilibrium

In summary, a new user of QCM is having trouble reaching equilibrium despite following the proper steps and cleaning the necessary components. The frequency sometimes fluctuates and the user is seeking suggestions from experienced QCM users. Possible reasons for the issue include insufficient vibration isolation, external vibrations, and improper mounting of the crystal. It is unclear if the QCM is a new system.
  • #1
dorins
1
0
Hi guys,

I am a new user of QCM and I am having trouble reaching equilibrium. I have isolated the chamber from air flows and vibrations, the crystals are clean and all the other removable parts have been cleaned as well.
The real problem is that sometimes I have managed to reach equilibrium by doing the exact same steps but 4/5 tries the frequency just giggles around in both air and water interfaces.

I do not know what else to try.

If any experienced users of QCM have suggestions, they would be very welcome and I would be very thankful.
 
Physics news on Phys.org
  • #2
I'm assuming you're using it for monitoring deposited film thickness?

If you tell me which company made your quartz crystal monitor, I'll see what I can scrounge up.
 
Last edited:
  • #3
How are you pumping down the system to achieve a vacuum? Your vibration isolation may be insufficient. Or your station is picking up vibrations from another external source, particularly if you are located in an upper floor of a building.

If those are not the answer, there may be a problem with the mounting of the crystal.

There are other possibilities. Is this a new system?
 

1. What is a Quartz Crystal Microbalance (QCM)?

A Quartz Crystal Microbalance (QCM) is a sensitive analytical instrument that is used to measure small changes in mass at the surface of a quartz crystal. It operates based on the principle of piezoelectricity, where the crystal oscillates when an alternating voltage is applied to it. The frequency of the oscillation is affected by any mass changes on the crystal surface, making it a powerful tool for studying surface interactions.

2. How does a QCM achieve equilibrium?

A QCM achieves equilibrium by measuring the frequency changes of the crystal over time. As the crystal is exposed to a substance, molecules from that substance will adsorb onto the crystal surface, causing a decrease in frequency. The QCM will continue to measure the frequency until it reaches a steady state, indicating that equilibrium has been achieved.

3. What factors can affect QCM equilibrium?

There are several factors that can affect QCM equilibrium, including the type of substance being measured, the temperature of the system, the frequency and amplitude of the applied voltage, and the surface properties of the crystal. It is important to control these variables in order to accurately measure and interpret the data from a QCM experiment.

4. What types of interactions can be studied with a QCM?

A QCM can be used to study a wide range of surface interactions, including adsorption/desorption processes, chemical reactions, and biological interactions. It is commonly used in fields such as material science, biochemistry, and environmental science to understand the behavior and properties of different substances and their interactions with surfaces.

5. What are the advantages of using a QCM for equilibrium studies?

The main advantages of using a QCM for equilibrium studies are its high sensitivity, real-time monitoring capabilities, and non-destructive nature. It can detect mass changes at the nanogram level, providing highly accurate and precise measurements. The real-time monitoring allows for dynamic measurements and the non-destructive nature of the technique means that the same sample can be used for multiple measurements, making it a cost-effective and efficient tool for equilibrium studies.

Similar threads

B Understanding thermodynamic equilibrium
    • Thermodynamics
Replies
3
Views
1K
How can I successfully grow high-quality KDP crystals?
    • Chemistry
Replies
3
Views
2K
Testing the piezoelectric properties of Quartz Crystals
    • Electromagnetism
Replies
4
Views
3K
I Estimating a thermal equilibrium on a custom made fridge
    • Thermodynamics
Replies
23
Views
1K
Vibrational modes of quartz crystal
    • Classical Physics
Replies
1
Views
1K
Getting Started with Application Development
    • Programming and Computer Science
Replies
6
Views
1K
I Irreversible adiabatic processes & entropy change (clarification needed)
    • Thermodynamics
Replies
22
Views
2K
Pressure drop / dissolved oxygen
    • Mechanics
Replies
4
Views
957
I Graduation of air flow inside a vacuum chamber
    • Classical Physics
Replies
4
Views
1K
Compressed Air Engine Calculations
    • Mechanical Engineering
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top