Local Piezoelectric Properties of Doped Biomolecular Crystals

Materials

David Ehre¹  Igor Lubomirsky¹  Shiri Dishon¹  Andrei Kholkin²  Vladimir Shur²  Denis Alikin² 

[1] Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Herzl St 234, Rehovot 7610001, Israel;School of Natural Sciences and Mathematics, Ural Federal University, 620000 Ekaterinburg, Russia;

关键词: α-glycine;    piezoelectricity;    doping;    piezoresponse force microscopy;   

DOI  :  10.3390/ma14174922

来源: DOAJ

【 摘 要 】

Piezoelectricity is the ability of certain crystals to generate mechanical strain proportional to an external electric field. Though many biomolecular crystals contain polar molecules, they are frequently centrosymmetric, signifying that the dipole moments of constituent molecules cancel each other. However, piezoelectricity can be induced by stereospecific doping leading to symmetry reduction. Here, we applied piezoresponse force microscopy (PFM), highly sensitive to local piezoelectricity, to characterize $\left(0\overline{1}0\right)$ faces of a popular biomolecular material, α-glycine, doped with other amino acids such as L-alanine and L-threonine as well as co-doped with both. We show that, while apparent vertical piezoresponse is prone to parasitic electrostatic effects, shear piezoelectric activity is strongly affected by doping. Undoped α-glycine shows no shear piezoelectric response at all. The shear response of the L-alanine doped crystals is much larger than those of the L-threonine doped crystals and co-doped crystals. These observations are rationalized in terms of host–guest molecule interactions.

【 授权许可】

Unknown