Coupling of the surface plasmon resonance with ferroelectricity in “DMAAlS crystal + silver nanoparticles” composite

On the basis of comparative study of the morphology of silver nanoparticles deposited on a surface of single crystalline NH2(CH3)2Al(SO4)2 × 6H2O (DMAAlS) and glass as well as of the absorption spectra of these composites the impact of the ferroelectric phase transition of the “order–disorder” type on the surface plasmon resonance (SPR) was investigated.The observed anomalies of the SPR band parameters were explained in terms of the resonance type coupling between the dipole clusters arising in a narrow region in vicinity of the Curie point and the free electrons within the silver nanoparticles. It was shown that such a coupling is followed by decreasing of these particles’ polarizability under the influence of a high frequency electric field of the propagating light photons. The mechanism of growth of the peculiar type of the silver nanoelements on the surface of DMAAlS single crystals—so-called nanowells—is proposed.