SYNTHESIS AND CHARACTERIZATION OF CACU3TI4O12 SUBTITUTED BY ZN AS DIELECTRIC MATERIAL

• Main Author: RONA MAYANGSARI (NIM : 20510026); Pembimbing: Dr. Bambang Prijamboedi , TIRTA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/17413
• Institution: Institut Teknologi Bandung

CaCu3Ti4O12 (CCTO) has attracted much attention because it possess a giant dielectric constant while having a non-ferroelectric behaviour at wide range temperature (100 K – 600 K). CCTO is a body centered cubic (bcc) perovskite <br /> <br /> <br /> <br /> AA'BO3 with Ca at A site, Cu at A' site, and Ti at B site. TiO6 octahedral is tilted to make Ca to have a bcc structure. In this study, full and partial substitution of A' site by Zn with stoichiometry CaCu3-xZnxTi4O12 were investigated. Synthesis of samples were done by solid state reaction with calcinations for x = 0; 0,5; 1; and 3 at 850 oC for 10 h and sintered at 1050 oC for 3 x 12 h. Calcination for sample x = 3 was carried at 750 oC for 12 h and sintered at 950 oC for 3 x 12 jam. XRD was used for structure analysis, where the measurement was carried out from 20 = 10o to 90 o. XRD pattern for x = 3 shows there are unknown peaks at 20 = 31-32o, 58o, and 68o. Peaks of CaTiO3 with high intensity was observed at 20 = 35o. Another impurity that observed at every sample was CuO. The dielectric constant was measured by capacitance measurement using LCR meter Agilent E4980, AC ionic conductivity was investigated by converting real and imaginer dielectric constant from capacitance to resistance, while conductivity for direct current was done by DC measurements with 4 probes method and 2 probes method using FLUKE 45 Dual Display Multimeter and Ultra High Resistance Meter, respectively. Both capacitance and conductivity measurement were carried at 373 – 673 K at ambient atmosphere. Dielectric constant for x = 0, 0.5, 1, and 1.5 is -105 and for x = 3 is -103. Sample x = 0.5 gives higher dielectric constant than x = 0 at both low and high temperature, while x = 3 gives the lowest dielectric constant. From conductivity measurement samples x = 0, 0.5, 1.5, and 3 gives conductivity -10-4 S/cm at high temperature and drop to -10-7S/cm at low temperature. From the results it can be concluded that x = 0, 0.5, 1.5, and 3 is semiconductor. Sample x = 1 is a metallic with conductivity >1 S/cm and increased with lowering temperature.