Morphology characterization and dielectric performances of Ce-doped barium strontium titanate powders prepared by modified citrate method

ABSTRACT

Citrate acid (CA), ethylene glycol (EG), and absolute ethyl alcohol (AEA) were combined to synthesize 0∼5% mol cerium doped barium strontium titanate (Ce-BST) powders, and the morphology characterization and dielectric performances of the powders were studied. X-ray diffraction (XRD) shows that the powders have ABO₃ perovskite structures with no secondary phase until ≥4% mol because AEA avoids the formation of cerium hydroxide caused by the hydrolyzation of Ce³⁺ ions, and Ce³⁺ ions enter into lattices to make lattice parameters increase. Scanning electronic microscope (SEM) reveals that Ce³⁺ ions affect grain growth and refine grain size with uniform grain size of about 100 nm at 2 mol%. Permittivity and loss tangent of the doped powders are decreased, where 2 mol% corresponds to the optimum dielectric properties with permittivity of 58 and loss of 0.007 at 1 GHz, which can meet the requirements in many applications like microwave devices. The relation between dielectric properties and Ce doping is also discussed.

KEYWORDS:

• BST
• cerium dopant
• citrate process
• morphology characterization
• dielectric performance

Funding

The paper is supported by the National Natural Science Foundation of China of 51172034, 61301052 and 61474016, the field of equipment development fund of 61409220110, the National Defense Science and technology innovation special zone project of 17-163-13-ZT-009-125-001, the International cooperation project of Sichuan Provincial Department of science and technology (2017HH0067), and the Sichuan science and technology support projects of 2017GZ0105.

Additional information

Funding

National Natural Science Foundation of China [51172034]; Field of equipment development fund [61409220110]; National Natural Science Foundation of China [61301052]; Sichuan Science and Technology Program [2017GZ0105, 18ZDYF2412]; International cooperation project of Sichuan Provincial Department of science and technology [2017HH0067]; National Natural Science Foundation of China [61474016]; National Defense Science and technology innovation special zone project [17-163-13-ZT-009-125-001].