A series of ANb2O6 (A=Ca, Mg, Cu, Ni) columbites and 50% Ni doped with CaNb2O6,MgNb2O6 and CuNb2O6 has been prepared using sol-gel technique. The samples were sintered at 9000C for 6 hours. Structural characterization of the prepared samples has been done using X-ray diffraction (XRD) method. To study their applicability in low temperature cofired ceramic (LTCC) technology, dielectric and thermal properties have been characterized. Microwave dielectric properties like dielectric constant and Qf values over Ku-band for all the compositions have been measured. Dielectric constant was found to fall between 4.8 to 10. Thermal properties like thermal conductivity and thermal coefficient of expansion (TCE) were measured over a temperature range from room temperature to 900 0C. Thermal conductivity was found to be of the order of 1-2 W/m 0K while TCE was of the order of 5-10 x 10-6/0C. TCE of some of the compositions have shown negative value at 900 0C.
Jyotirmayee Satapathy and Reddy, M. V. Ramana, “Dielectric and Thermal Studies of ANb2O6 (A=Ca, Mg, Cu, Ni) for LTCC Application”, International Journal of Applied Physics and Mathematics, vol. 7, 2011.