Engineering of Pyroelectric Crystals Decoupled from Piezoelectricity as Illustrated by Doped α-Glycine

Design of pyroelectric crystals decoupled from piezoelectricity is not only a topic of scientific curiosity but also demonstrates effects in principle that have the potential to be technologically advantageous. Here we report a new method for the design of such materials. Thus, the co-doping of centrosymmetric crystals with tailor-made guest molecules, as illustrated by the doping of alpha-glycine with different amino acids (Threonine, Alanine and Serine). The polarization of those crystals displays two distinct contributions, one arising from the difference in dipole moments between guest and host and the other from the displacement of host molecules from their symmetry-related positions. These contributions exhibit different temperature dependences and response to mechanical deformation. Thus, providing a proof of concept for the ability to design pyroelectric materials with reduced piezoelectric coefficient (d(22)) to a minimal value, below the resolution limit of the method (<0.005 pm/V).

Automated summary

This study reports a new method for designing pyroelectric crystals decoupled from piezoelectricity. By co-doping centrosymmetric crystals with tailor-made molecules, the polarization of the crystals exhibits two distinct contributions, providing proof of concept for designing pyroelectric materials with reduced piezoelectric coefficient.