Effect of Ga3+ substitution on the microwave dielectric properties of 0.67CaTiO3–0.33LaAlO3 ceramics. Issue 6 (1st May 2016)

• Record Type: Journal Article
• Authors: Dou, Zhanming; Jiang, Juan; Wang, Gan; Zhang, Fan; Zhang, Tianjin
• Is Part Of: Ceramics international. Volume 42:Issue 6(2016)
• Page Start: 6743
• Page End: 6748
• Publication Date: 2016-05-01
• Subjects: Ga-doped microwave dielectric ceramics -- Polarizability -- Tolerance factor -- Bond valence; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2016.01.046
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: 0.67CaTiO3 –0.33La(Al1− x Ga x )O3 (0≤ x ≤0.4) (CTLAG) ceramics with pure perovskite structure were prepared by a conventional two-step solid-state reaction process. The effect of Ga 3+ substitution for Al 3+ on the microwave dielectric properties of the ceramics was subsequently investigated. As Ga content increased, the ionic polarizability increased and led to an increase of the dielectric constant ( ε r ). Meanwhile, both the tolerance factor ( t ) of CTLAG ceramics and A-site bond valence were considered to have effect on the temperature coefficient of the resonant frequency ( τ f ) with the increase of Ga content. Results also showed that the quality factor ( Q × f ) varied with increasing Ga 3+ content because of not only intrinsic factor but also extrinsic factors such as the bimodal grain size distribution, the variation of relative density, and the packing fraction. Excellent microwave dielectric properties with ε r ≈45.81, Q × f ≈34, 152 GHz, and τ f ≈3.09 ppm/°C were achieved for 0.67CaTiO3 –0.33La(Al0.9 Ga0.1 )O3 ceramics sintered at 1420 °C for 4 h.