Structure and microwave dielectric properties of Ca0.66La0.387Ti0.88O3 ceramics

Abstract

Ca 0.66 La 0.387 Ti 0.88 O 3 microwave dielectric ceramics were prepared via a mixed oxide solid state sintering route and characterized. X-ray diffraction revealed the formation of single phase Ca 0.66 La 0.387 Ti 0.88 O 3 ceramics with orthorhombic (Pbnm) symmetry within the detection limit of the in-house XRD facility. Raman spectroscopy revealed the presence of seven Raman active bands evident of orthorhombic symmetry, in agreement with the present X-ray diffraction results. The microstructure of sintered samples appeared almost dense with some occasional pores. Ca 0.66 La 0.387 Ti 0.88 O 3 exhibited reasonable relative permittivity (*71.5) and quality factor (*13,407 GHz); however, its temperature coefficient of resonance frequency was high (*136.4 9 10 -6 /°C) for commercial applications and requires further optimization.

Low temperature sintering and microwave dielectric properties of CoZrNb2O8 ceramics with H3BO3 addition

“…For these high frequency wireless communication applications, the microwave dielectric materials should have a high dielectric constant, a high quality factor, and a near-zero temperature coefficient of resonant frequency, which are desirable for minimization of the microwave circuit component, maximum signal intensity and adaptation to environmental temperature changes [5,6]. At present, many compounds were reported for the possible use in microwave applications [7][8][9][10]. Among of several kinds of dielectric ceramics, wolframite-type CoZrNb 2 O 8 ceramics possess a high quality factor combined with appropriate dielectric constant, which are suitable candidate materials for contemporary miniaturized and integrated passive components application [11][12][13].…”

Sintering behavior and microwave dielectric properties of CaTi1-x(Nb1/2Al1/2)xO3

“…The effect of La substitution for Ca in CaTiO3 with general formula Ca1-xLa2x/3O3 was exhibited Q×fo =17600 GHz, εr =109, τf =+213 ppm/°C at x=0.4 [7]. Ca0.66La0.387Ti0.88O3 possess high Q×fo =13407 GHz and εr =71.5 but a poor τf =+136.4 ppm/°C [8]. Feteira et al [9] observed a decrease in εr from 170 to 12, while an increase in Q×fo from 10000 to 12000 GHz in compositions Ca1-xYxTi1-xAlxO3 (x=0.1).…”

Magnetic and thermoelectric properties of REMoN3 (RE = La, Ce, Pr, Nd, and Sm): A first‐principles study

“…They have the potential to show attractive physical and chemical properties tuned by doping without considerable change in the crystal structure [10, 11]. Perovskites are generally represented by ABX 3 , where A and B represent metallic cations (usually very different in size), and X denotes an anion [12]. Their unique physical properties make them potential candidates for industrial applications [6–8, 13].…”