Comparison between Samarium doped nickel oxide and Samarium added nickel oxide on dielectric properties

Pure Nickel Oxide (NiO) is an insulators materials at room temperature. This insulator are one of the target materials that were studied to improve its dielectric properties. Many researchers found that NiO can exhibits high dielectric constant (εo) with value 103-105 by doping with another materials through formula AxByNi1-x-yO (where A for monovalent materials and B for transition materials). They claimed that doped with rare earth materials with NiO will improve the dielectric properties of NiO. In this research, the effect of Samarium Oxide (Sm) doped (mol%) NiO as dopant and added (wt%) in NiO as ceramic composite were investigated. The comparison of both doped ceramic and added ceramic in their dielectric properties were studied. The both electroceramic of Ni(1-x)SmxO and NiSmO3 were prepared by using solid state reaction method. Samarium was added with five different concentrations, which are 0.01, 0.02, 0.03, 0.05 and 0.10 mol% for dopant and another five different concentrations which are 1, 2, 3, 4 and 5 wt% for addition in NiO. The preparation started by milling the raw materials for 24 hours with alumina ball and then followed by calcination at 950 ºC for 4 hours. The calcined powders were compacted into a cylinder pellet (10 mm) shape by applying 250 kPa and were characterized by using X-Ray Diffraction (XRD) for phase formation, Scanning Electron Microscope (SEM) for morphology, Impedance Analyzer for dielectric properties and densification by using Archimedes’ principle. The XRD results shows that the both ceramic doped and added samples did not change the NiO cubic structure. Besides, high concentration of Sm caused the lattice parameter of NiO increased. Apart from that, SEM shows both samples full of pores and some of the samples shows the agglomeration of Sm materials. Bulk density shows the highest density of both samples were at concentration 0.03 mol% and 3.0 wt% of Sm. The dielectric behaviour was observed in frequency range of 100 to 100 000 Hz. The optimum composition for Ni(1-x)SmxO and NiSmO3 was obtained at x = 0.01 mol% and 5.0 wt% sample with highest εo (2.4 x 104 and 9.3 x 104), respectively but at the sme time they exhibits high dielectric loss (tan δ) with value 4.9 and 10.48, respectively.