University of California, Santa Barbara
Faculty Sponsor's Department(s):
High dielectric permittivity of Lithium (Li) and Titanium (Ti) substituted NiO ceramics for microelectronic applications
The purpose of this project is to use a variety of experimental methods and analytical techniques to evaluate LTNO (Lithium (Li) and Titanium (Ti) substituted NiO) fabrication and the colossal dielectric properties of the LTNO system. These ceramics have attracted attention due to their high dielectric permittivity, low cost, and lead free composition. They see potential in future microelectronics such as capacitors, field effect transistors, and memory devices. The LTNO system (Li0.1(TixNi1-x)0.90O; x=0.05, 0.10, 0.15) was synthesized by a high-temperature solid-state ceramic reaction method. The effect of the Ti content on the crystal structure, chemical bonding, and magnetic, dielectric, and electrical properties of the LTNO ceramics is evaluated. The structural properties of the ceramics were analyzed using X-ray Diffraction (XRD) and Raman spectroscopic studies. The microstructure was studied using a scanning electron microscope (SEM), and the temperature dependent dielectric properties were measured using an Impedance Analyzer. The X-ray diffraction measurements revealed the formation of single phase cubic NiO phases; however, secondary phases were evolved for higher values of Ti-content in LTNO. The dielectric properties are investigated as a function of frequency (102-106 Hz) at different temperatures (20°C-200°C). The SEM results indicate monolithic grain growth with increasing Ti content in LTNO. A structural, chemical, and dielectric property correlation in LTNO is presented and discussed.