Zirconium dioxide or “Zirconia,” an oxidized form of the metal “zirconium” (Zr), is known for its high melting point. Its crystal structure is a Ditetragonal dipyramidal structure, categorized in the P4₂/nmc space group. This pyramid forms along the lattice constant of the material on the upper layer, and contributes to a single crystal form of that upper layer material. This is a key aspect of KRYSTAL’s single crystal technologies.
Bottom electrode film
Pt Bottom electrode substrate (Pt/ZrO₂)
Pt demonstrates low resistance and forms thin films easily, so it is often used as an electrode in film forming for piezoelectric elements. Based on the customer’s specifications, we provide Pt film formed on ZrO₂.
SRO Bottom electrode substrate (SRO/Pt/ZrO₂)
Strontium ruthenium oxide (SRO; SrRuO₃) is a type of ferro-magnetic metal oxide, and a Ruddlesden-popper type compound. The crystal structure is a perovskite structure, and film stability is increased by forming the film on a Pt film. ZrO₂/Pt/SRO is used in KRYSTAL’s standard spec bottom electrode film.
PZT (for Actuators)
One of KRYSTAL’s two types of Lead zirconate titanate (PZT) products, developed especially for Actuator applications.
These products feature well-balanced specifications, offering a high d-constant and withstand voltage, and a low dielectric constant. They are designed for applications that use inverse piezoelectric effects.
Actuator applications in various devices
PZT (for Sensors)
One of KRYSTAL’s two types of Lead zirconate titanate (PZT) products, developed especially for Sensor applications.
These products have a strong c-axis orientation, and the relative dielectric constant is reduced to 140 or less, in order to increase the electric charge generated by distortion.
They are designed for applications that use piezoelectric effects.
Sensor applications in various devices
Top electrode (Pt/SRO/PZT)
At the customer’s request, we deliver SRO+Pt film formed on top of PZT film, as a top electrode.
Lead-free thin film materials
PZT film demonstrates outstanding characteristics and is used in various applications, but because this material contains a lead component, in recent years, applications are at times limited from the perspective of impact on the environment and health. KRYSTAL is working to develop lead-free materials that demonstrate characteristics equivalent to or better than PZT film. For example, we have already succeeded in creating single crystal piezoelectric film using BTO, ALN, LaNbO₃, LaTiO₃, and KNN, among others. We will continue our untiring efforts to develop new materials that meet our customers’ needs.
E.g.: RF filters
We are always developing new products using KRYSTAL’s single crystal technologies. We will introduce these new materials as they become available.