Advanced Electro Ceramics

Piezoelectric Hemispheres

CeramTec is a world leader in the design and manufacture of complex electronic ceramic components and assemblies used in a wide range of applications and cutting edge technologies.

CeramTec’s Global Electroceramics Division specialises in the development and production of various hemisphere and focal bowl sizes, electrode and metallisation configurations. This range is fabricated from 33 available piezoelectric material formulations to address high power, sensitivity, stability needs in cryogenic temperatures as also in high temperatures and extreme pressure applications.

Applications include

  • Sonar transducers
  • Hydrophones
  • HIFU medical and industrial
  • Underwater communications


  • Choice of metallisation (Silver, Nickel, Gold and others on request)
  • Evaporated and chemically deposited metallisation's available
  • Thickness frequency tuning available on request
  • Wide choice of PZT formulations

Typical Electrode Configurations

Standard Hole in apex Custom Custom Focal Bowl

Other custom electrode configurations are available on request.

Dimensional Range (Hemisphere/ focal bowl)

  From To
Outside Diameter/ Diameter 6mm (0.24”) 152.4mm (6”)
Wall thickness / Thickness 1mm (0.04”) 10mm (0.39”)

Parts can be produced to the size ranges shown, but not in every combination of dimensions expressed above.

Standard Mechanical Tolerances

Outside diameter/ diameter ±0.150mm
Wall thickness / Thickness ±0.05mm

Tighter mechanical tolerances are achievable but are dependent on the plate length, width and thickness.

Metallisation Type

Silver fired thick film Evaporated Nickel
Electroless nickel Gold flash
Tin Evaporated Gold and others available on request

Typical Impedance Response Trace (Radial Resonance)

The above is a typical impedance trace measured on a dedicated analyser and depicting the resonance and anti-resonance points associated with the ring shaped component. This data allows the calculation of piezoelectric activity and other important characteristics required for the application.

Useful Equations

Radial frequency
Thickness frequency
Static displacement
Voltage (static)
Effective coupling factor
Planar coupling factor
Mechanical quality factor

Ceramic Testing

Appropriate statistical methods ranging from AQL’s to 100% testing are used on electrical parameters in accordance with EN-50324-1. A brief summary is provided in hard copy and typically includes low field measurements of capacitance, tan delta and the main parameters used to determine piezoelectric activity. Procedures other than this can be negotiated, and additional data requirements (electronic format, sample quantity, etc) are available on request.

There is more to discover…

With the acquisition of the Electro-Ceramics Division from Morgan Technical Ceramics, CeramTec has broadened its already extensive range of piezo-ceramic materials and products.

Discover the wide portfolio and expert know-how.

Recommended Contacts

Please click on the button “Contacts” to the right, to get a list with the personal and direct responsible contacts within the CeramTec Group.