Piezoelectric Transducer Crystals
Transducer crystals are custom made to order from Quartz, Lithium Niobate, Tourmaline, Gallium Orthophosphate or Lead Zirconate Titanate (PZT) .
Transducers themselves are used in many applications, such as ultrasonic pressure measurement, level sensing, distance sensing, micro-positioning, non-destructive testing of solids and acousto-optical experiments.
Soldered wire leads, suitable to the size and frequency of the crystals, are available.
Quartz
Single-Crystal Quartz can be fabricated to generate compressional, shear, length extensional and torsional waves for use in numerous applications.
Single Crystal Quartz is often used in research applications due to its high repeatability, superior ageing characteristics and purity of modes. Crystal Quartz is the standard to which other transducer materials are compared. It is not as efficient as other materials and its extremely high Q may be detrimental in certain applications.
Available frequency range is between 50Khz and 100Mhz depending on shape and size.
Lithium Niobate
Lithium Niobate possesses a high Curie temperature and excellent piezoelectric coupling coefficient making it attractive for ultrasonic device applications.
Lithium Niobate possesses a number of useful cuts that are now extensively used in transducer applications. Two compressional cuts are popular, the Z cut and the 36°C rotated Y-cut. It is suitable for applications from 250Khz to 40Mhz.
Lithium Niobate possess very large piezoelectric coupling coefficients - several times larger than quartz - and very low acoustic losses. Because of its Curie temperature of 1150°C it can be utilised in high temperature applications.
Gallium Orthophosphate
Gallium Orthophosphate, GaPO4 is a single crystal material developed in the 1980s primarily for the manufacture and design of high temperature sensors. The material is purely piezoelectric (no pyroelectric discharge) and has excellent high temperature properties up to 970°C, with excellent stability of many physical constants.
In additon, the material has high electric resistivity and a high piezo-electric constant and sensitivity. Various angles of orientation are available and element sizes are around 1" diameter.
Lead Zirconate Titanate (PZT)
Lead Zirconate Titanate (PZT) is available in a variety of grades with a wide range of properties to fulfil the many diverse applications of piezoelectricity. We can supply discs, blocks, tubes, rings and custom shapes from various grades of material in both compressional and shear wave modes. Frequency range is 100Khz to 20Mhz ± 5%.
PZT is ideal for a broad range of applications such as: nano-positioning, medical therapeutics, flow sensing and non-destructive testing to name but a few.
Shape can be:
- round
- square
- rectangular
- triangular and wedged
- conical
- tubular
- cylindrical
- spherical
- annular
General Specifications
| Material | Mode of Vibration | Fundamental Frequency Range | Tolerances | Typical Flatness | Typical Parallelism | Minimum Diameter | Maximum Diameter |
|---|---|---|---|---|---|---|---|
| Quartz | Compressional, Shear, Length Extensional, Torsional | 50 KHz - 100 MHz | ± 5% | To within 0.00002" | To within 0.00005" | 0.02" | 8" |
| Lithium Niobate | Compressional, Shear, Triple Mode | 250 KHz - 40 MHz | ± 5% | To within 0.00002" | To within 0.00005" | 0.02" | 6" |
| Lead Zirconate Titanate | Compressional, Shear, Dual Mode | 100 KHz - 30 MHz 40 MHz |
± 5% ± 10% |
To within 0.00005" | To within 0.000015" | 0.02" | 6" |
Standard Finishes
| Fundamental Operation | Overtone Operation |
|---|---|
| 3 micron fine lapped | proprietary chemical polish (flatness and parallelism will vary) |
Vacuum-deposited Electrodes enable the best possible frequency match in a diversity of patterns. These thin (≈ 3000Å) electrodes maintain the flatness, parallelism and surface quality of the crystals and do not overload thin, high frequency crystals.
Standard electrodes are vacuum-deposited chrome/gold, chrome/silver, chrome, copper, titanium, and aluminium. Electroless nickel, copper and gold, and fired palladium/silver, silver, gold and platinum/gold are also available.
Numerous individual patterns, and custom masks can be made to your specifications.