The pyroelectric effect appears in materials that generate large electric fields at high temperatures. Voltages produced can be large enough to accelerate particles to speeds useful in particles accelerators and eve to initiate nuclear fusion. Often the effect is temporary as charges move from within or outside the material.
Materials that exhibit this phenomenon can be used to detect temperate changes The phenomenon arises because heating a material sometimes produces polarisation and a potential difference across a material e.g. boron aluminium nitrid.>/BR> Piezoelectricity and pyroelecricity are closely related and most piezoelectric materials are also pyroelectric.