Microwave dielectric properties of La sub(5)(Ti sub(4)B)O sub(17) and Nd sub(5)(Ti sub(4)B)O sub(17) (B = Cr, Fe) ceramics

• Published in: Journal of materials science. Materials in electronics Vol. 26; no. 3; pp. 1918 - 1922
• Main Authors: Muhammad, Raz, Iqbal, Yaseen, Rambo, Carlos Renato
• Format: Journal Article
• Language: English
• Published: 01-03-2015
• Subjects: Chromium; Coefficients; Density; Dielectric properties; Diffraction; Iron; Materials science; Microwaves; Symmetry
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-014-2630-7

Compositions in the A sub(5)B sub(5)O sub(17) (A = La, Nd, B = Cr, Fe) series were processed through a mixed oxide solid state sintering route. X-ray diffraction revealed an orthorhombic (Pnnm) symmetry for La sub(5)Ti sub(4)FeO sub(17) and monoclinic (P2 sub(1)/b) symmetry for Nd sub(5)Ti sub(4)FeO sub(17), associated with the higher tolerance factor of Nd sub(5)Ti sub(4)FeO sub(17) than Nd sub(5)Ti sub(4)CrO sub(17). The compounds exhibited relative permittivity epsilon sub(r) ~27-37, Quality factor Qf sub(o) ~5,735-7,419 GHz and temperature coefficient of resonance frequency tau sub(f) ~ -23.86 to -104 ppm/ super(o)C. The observed low density indicated that the microwave dielectric properties can be improved by improving the density, and tau sub(f) can be tuned through zero via partial substitution of Sr at the A-site.