Zirconium oxide (ZrO2), also known as zirconia, is a refractory metal oxide ceramic that is widely used as a substrate material. Zirconia substrates have a high mechanical strength, good thermal stability, and a high resistance to thermal shock, making them suitable for high-temperature applications. They also have excellent electrical insulation properties, high hardness, and a high melting point, which makes them ideal for use in electronic components, such as capacitors, resistors, and inductors. Additionally, zirconia substrates can be used as substrates for the growth of thin films, such as those used in sensors, fuel cells, and batteries. The transparency of zirconia to visible light and its high refractive index make it an attractive substrate for optical devices, such as waveguides and lenses.