The memory effect of Dy_2.8Sr_0.2Fe₅O₁₂(DySrIG) nanoparticles

Abstract

Dy2.8Sr0.2Fe5O12 (DySrIG) was prepared using the citrate–nitrate auto-combustion method. Single phase garnet with cubic structure was obtained at 1100 °C. Thermal hysteresis (heating–cooling) study was performed for the following physical properties: crystal structure using x-ray diffraction (XRD); magnetic susceptibility using Faraday’s method; dielectric measurements including dielectric constant as well as ac conductivity using an LCR meter. The results of the study reveal hysteresis loops in all the parameters which agree with those appearing in differential scanning calorimetry (DSC), and the former were interpreted according to the accompanying changes in the structural characterizations. The study clarifies that the investigated nanoparticles of DySrIG possess an electric memory effect with thermalization, where their dielectric parameters have sensitive changes with temperature in the range 25–400 °C and return to their original values at room temperature again. Accordingly, DySrIG could be recommended in thermal electric sensor applications (thermistors).

Fundamental formulations and recent achievements in piezoelectric nano-structures: a review

“…27 Ahmed et al investigated the nanoparticles of DySrIG, and found that they possess an electric memory effect with thermalization, where their dielectric parameters have sensitive changes with temperature in the range 25-400 C and return to their original values at room temperature again. 28 Fu et al developed a new separator for lithium-ion batteries by depositing SiO 2 ceramic layers of nanoparticles onto the polypropylene separators and using a simple yet effective SiO 2 formation and deposition process. 29 (Bi 0.5 Na 0.5 )TiO 3 doped with 8 mol% BaTiO 3 particles with average size of 50 nm was compacted and sintered by spark-plasma-sintering method, and it is found that increasing the sintering temperature from 800 to 900 C can lead to the increase of piezoelectric coefficient d 33 .…”