Zirconium Oxide (ZrO2) General Information
Zirconium oxide is a chemical compound with a chemical formula of ZrO2. It is often referred to as zirconia. It is white in appearance with a melting point of ~2,700°C, a density of 5.89 g/cc, and a vapor pressure of 10-4 Torr at ~2,200°C. Due to its resistance to cracks, zirconium oxide is heavily utilized for ceramic production. Cubic zirconia, which is zirconium oxide in cubic crystalline form, is sold by jewelers as a low-cost alternative to diamonds. Zirconium oxide is evaporated under vacuum for optical coatings, semiconductors, and fuel cells.
Zirconium Oxide ZrO2 Specifications
|Material Type||Zirconium Carbide|
|Melting Point (°C)||3,540|
|Theoretical Density (g/cc)||6.73|
|Type of Bond||Indium, Elastomer|
|Temp. (°C) for Given Vap. Press. (Torr)||10-4: ~2,500|
|Export Control (ECCN)||1C234|
Empirical Determination of Z-Factor
Unfortunately, Z Factor and Shear Modulus are not readily available for many materials. In this case, the Z-Factor can also be determined empirically using the following method:
- Deposit material until Crystal Life is near 50%, or near the end of life, whichever is sooner.
- Place a new substrate adjacent to the used quartz sensor.
- Set QCM Density to the calibrated value; Tooling to 100%
- Zero thickness
- Deposit approximately 1000 to 5000 A of material on the substrate.
- Use a profilometer or interferometer to measure the actual substrate film thickness.
- Adjust the Z Factor of the instrument until the correct thickness reading is shown.
Another alternative is to change crystals frequently and ignore the error. The graph below shows the % Error in Rate/Thickness from using the wrong Z Factor. For a crystal with 90% life, the error is negligible for even large errors in the programmed versus actual Z Factor.