Reaction of CdCl_(2) with cyclopentylamine in the presence of aqueous HCl affords an ABX_(3)-typed perovskite structure compound[C_(5)H_(9)-NH_(3)][CdCl_(3)](1).Above 300 K,it is in a paraelectric phase with a centros...Reaction of CdCl_(2) with cyclopentylamine in the presence of aqueous HCl affords an ABX_(3)-typed perovskite structure compound[C_(5)H_(9)-NH_(3)][CdCl_(3)](1).Above 300 K,it is in a paraelectric phase with a centrosymmetric space group Cmcm,while below 300 K it has a noncentrosymmetric space group Cc,corresponding to a ferroelectric phase.The temperature-dependent dielectric constant shows a peak at about 300 K with a 12-fold enhancement which is confirmed by differential scanning calorimetry.The normalized pyroelectric and second-harmonic generation effect as functions of temperature are almost overlapped,probably indicating that the trends with temperature basically satisfy the Landau phenomenological theory,revealing a symmetry-breaking occurrence.The ferroelectricity,a spontaneous saturation polarization approximately reaching 1.7μC cm^(-2),is further confirmed by piezoresponse force microscopy.展开更多
基金supported by the Natural Science Foundation of China(NSFC)(grants no.21290172,21101025 and 91222101).
文摘Reaction of CdCl_(2) with cyclopentylamine in the presence of aqueous HCl affords an ABX_(3)-typed perovskite structure compound[C_(5)H_(9)-NH_(3)][CdCl_(3)](1).Above 300 K,it is in a paraelectric phase with a centrosymmetric space group Cmcm,while below 300 K it has a noncentrosymmetric space group Cc,corresponding to a ferroelectric phase.The temperature-dependent dielectric constant shows a peak at about 300 K with a 12-fold enhancement which is confirmed by differential scanning calorimetry.The normalized pyroelectric and second-harmonic generation effect as functions of temperature are almost overlapped,probably indicating that the trends with temperature basically satisfy the Landau phenomenological theory,revealing a symmetry-breaking occurrence.The ferroelectricity,a spontaneous saturation polarization approximately reaching 1.7μC cm^(-2),is further confirmed by piezoresponse force microscopy.
