A series of Ca_xMg_1-xNb₂O₆ (x=0,0.2,0.4,0.6,0.8,1) columbites has been prepared using sol-gel technique. The samples were sintered at 900°C for 6 hours. Structural characterization of the prepared samples has been done using X-ray diffraction (XRD) method. Microstructure has been studied using SEM. To study their applicability in low temperature cofired ceramic (LTCC) technology, elastic properties have been characterized for mechanical compatibility. Elastic behaviour was investigated at 300 K, employing ultrasonic pulse transmission technique at 1 MHz. The values of elastic moduli and acoustic Debye temperature (mD) were computed from longitudinal and shear velocities. The measured values were corrected to zero porosity using Hasselman and Fulrath's formula. The elastic constants of the samples, estimated using Modi's heterogeneous metal-mixture rule, were also reported. The variation of elastic moduli was interpreted in terms of strength of interatomic bonding.

Keywords: Columbite, sol-gel, elastic modulii, Debye temperature, LTCC