Organic Amine Surfactant Preparation Of Barium Titanate Nanoparticles And Its Dielectric Ceramic

In this paper, BaTiO₃ nanopowders and ceramics were prepared by sol-gel process using organic amines-n-butylamine(NBA), 1,6-hexanediamine(DH), and ethylenediamine(DE) as the surfactants. The xerogels, powders and ceramics were characterized by the methods of TG-DTG, DSC, XRD, SEM and TEM. The dielectric properties of the ceramics were measured by a LCR meter controlled by a computer. The powders with well dispersibility and the ceramics with good dielectric property were obtained. Besides, the influence of organic amines on BaTiO₃ and X7R BaTiO₃-based creamic was investigated. Moreover, X7R BaTiO₃-based ceramic materials with high dielectric constant were prepared using organic amines as the surfactant.The maximal dielectric constant was 11 717 and the dielectric loss was only 0.025 when the [Ti(OBu)₄]/[NBA] ratio was 1:1 and the calcining temperature was 900℃for 2 h and the sintering temperature was 1 300℃for 2 h; Besides, with the same concentration, the ceramics had better density, higher maximal and room-temperature dielectric constants with increasing of calcining temperature. The maximal dielectric constant was 11 122 when the [Ti(OBu)₄]/[DH] ratio was 1:1 and the dielectric constant was 4 905 at room temperature but the dielectric loss was only 0.027 when the calcining temperature was 900℃for 2 h and the sintering temperature was 1 250℃for 2 h. The maximal dielectric constant was 9 018, and the dielectric constant was 4 471 at room temperature but the dielectric loss was only 0.032 when the [Ti(OBu)₄]/[DE] ratio was 1:1.25 and the ceramics had a flatε-T curve of well dielectric property when the calcining temperature was 900℃for 2 h and the sintering temperature was 1 250℃for 2h.BaTiO₃ and X7R BaTiO₃-based ceramics with different organic amine-n-butylamine, 1,6-hexanediamine, ethylenediamine had been prepared by sol-gel process. The dielectric constant was greater than free organic amine, and the Temperature Characteries of the dielectric Constant of all samples were met the X7R. The dielectric property of X7R BaTiO₃-based ceramic was the best using the n-butylamine as the surfactant.