I want to know how the powdered formed of piezoelectric material is converted to crystal like used in quartz watches. I know that some more chemicals are mixed with the material and then it is pressed in form of tuning fork (for clocks) at particular temperature and pressure. So what are the chemicals, temperature and pressure which are used. How they are made to vibrate at that particular frequency?
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1$\begingroup$ Are you asking about how to prepare the ceramic materials PZT, or asking about the binder added to the the prepared PZT in order to process it? $\endgroup$– Yomen AtassiCommented Jun 4, 2015 at 9:11
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1$\begingroup$ Also remember that making piezoelectric quartz (which is intrinsically a polar crystal) is a bit different than making piezoelectric PZT (which is intrinsically a symmetric crystal). $\endgroup$– Geoff HutchisonCommented Jun 4, 2015 at 13:07
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Good quality quartz crystals for use in resonators can be found in nature, such as in Minas Gerais, Brazil. They can also be produced by crystallization in a hydrothermal process, simulating in the autoclave the same process that occurred over geologic epochs.
You can easily grow your own Rochelle salt (potassium sodium tartrate, $\ce{KNaC4H4O6·4H2O}$) piezoelectric crystals. Rochelle salt was commonly used in inexpensive crystal headphones and phonograph cartridges. The raw materials are household chemicals and the directions are straightforward. Again, these crystals are grown, not hot pressed.
Tuning forks watches such as the Bulova Accutron did not use crystals, but rather metal tuning forks, made from NiSpan C, with a low coefficient of thermal expansion, similar to invar. These did not rely on the piezoelectric effect, but on magnetic induction.
answered Jun 5, 2015 at 3:24