Premium
Novel scheelite‐type [Ca 0.55 (Nd 1‐ x Bi x ) 0.3 ]MoO 4 (0.2 ≤ x ≤ 0.95) microwave dielectric ceramics with low sintering temperature
Author(s) -
Hao ShuZhao,
Zhou Di,
Hussain Fayaz,
Su JinZhan,
Liu WenFeng,
Wang DaWei,
Wang QiuPing,
Qi ZeMing
Publication year - 2020
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17378
Subject(s) - scheelite , tetragonal crystal system , raman spectroscopy , analytical chemistry (journal) , materials science , ceramic , temperature coefficient , permittivity , sintering , dielectric , mineralogy , crystal structure , crystallography , chemistry , tungsten , physics , optics , metallurgy , optoelectronics , composite material , chromatography
Novel scheelite‐type [Ca 0.55 (Nd 1‐ x Bi x ) 0.3 ]MoO 4 (0.2 ≤ x ≤ 0.95) ceramics were prepared using the solid‐state reaction method. According to the X‐ray diffraction data, a solid solution was formed in 0.2 ≤ x ≤ 0.95 and all the samples belong to pure scheelite phase with the tetragonal structure. As revealed by Raman spectroscopy, the number of vibrational modes decreased with the increase in x value, which further indicated that Bi 3+ ions occupied A‐site of scheelite structure. As the x value increased, the sintering temperature decreased from 740°C to 660°C; the permittivity increased from 12.6 to 20.3; the Qf value first decreased slightly and gradually remained stable. Based on the infrared reflectivity spectrum analysis, the calculated permittivity derived from the fitted data shared the same trend with the measured value. The [Ca 0.55 (Nd 0.05 Bi 0.95 ) 0.3 ]MoO 4 ceramic sintered at 660 °C attained a near‐zero value temperature coefficient ~τ f (−7.1 ppm/°C) and showed excellent microwave dielectric properties with a ɛ r ~ 20.3 and a Qf ~ 33 860 GHz, making this system a promising candidate in the ultralow temperature cofired ceramic (ULTCC) technology.