HfO2 | Hafnium Oxide basic knowledge
HfO2 has a refractive index near 1.95 at 550 nm and a transmittance range from below 220 nm to 12 μm. HfO2 is a durable material with a high refraction index and a short-wave cut-off edge protruding into the near-ultraviolet (UV) region. It is widely used for UV multilayered coatings for high-performance applications and is also popular for laser applications, given its high laser-induced damage threshold.
Zr is not easily separated from HfO2, and so the purity values for HfO2 do not usually include Zr. However, our HfO2 product has very little Zr, allowing you to produce films with low absorption in the UV region. Moreover, the levels of other impurities also are extremely low.
It is well known that the laser-induced damage thresholds (LIDTs) of HfO2 thin films are significantly reduced by impurities, which absorb the incident radiation, causing rapid increases in temperature, and ultimately, melting, vaporization, or stress fracture of the film material around the impurity.