The physics of pyroelectric detectors is reviewed, including a discussion of response and electronic noise and their dependence on device design and material parameters Other sources of noise are described, particularly as generated by environmental effects such as microphony, together with techniques for their minimisation The range of ferroelectric materials which have been assessed for use in pyroelectric detectors is reviewed and their properties compared, particularly from the aspect of application to different types of devices Finally, an account is given of the wide range of applications for which pyroelectric detectors have been used, including a detailed description of both the pyroelectric vidicon and pyroelectric arrays and their application to thermal imagers

https://iopscience.iop.org/article/10.1088/0034-4885/49/12/002/pdf

Pyroelectric devices and materials

Correlation between microstructure, strain behavior, and acoustic emission of soft PZT ceramics

Damage evolution in ferroelectric PZT induced by bipolar electric cycling

When cycling a hysteresis loop, bursts of high frequency ultrasonic waves are emitted. This general phenomenon, which must not be confused with the classical magnetostrictive effect at twice the cycling frequency, is called the magnetoacoustic emission (MAE). By using literature and authors’ results, qualitative and quantitative, the authors review the past and present knowledge of the MAE phenomenon to stress its fundamental origin: the domain wall (DW) creation/annihilation processes. On a qualitative point of view, the shape demagnetizing effect is shown to drastically change the MAE profiles, which allow us to clearly distinguish the MAE from the classical magnetic Barkhausen noise. Quantitatively and in agreement with their interpretation, the authors have established that the total MAE activity along an hysteresis loop is proportional to the hysteresis losses during the same loop; this law has been confirmed on several series of polycrystalline ferrimagnets and is valid whatever the composition, the...

The magneto‐acoustic emission (invited)

Ferroelectric domains formed in the electric field of an atomic force microscope decay with time when the reversal voltage is removed. We propose a theory for this process. Dynamic equations describing the time evolution of the domain sizes are constructed and solved. It is shown that the larger the domains, the more stable they are. The time dependences of the domain length and base radius are qualitatively different. The radius of the domain decreases during the decay process, and for a large domain there is a plateau in its time dependence. In contrast to this, the length of the domain first does not decrease but rather grows significantly and then rapidly drops. We introduce the concept of critical radius for the domain stability. Only domains with a radius exceeding the critical radius have a long lifetime, which increases exponentially with the initial domain radius. The calculated value of the critical radius of stability in barium titanate is in reasonable agreement with the experiment. Possible m...

L Zammit Mangion

Papers

Acoustic emission from domain wall motion in ferroelectric lead germanate

A threshold electric field for acoustic emission from ferroelectric Rochelle salt