Different Additives Doped Ca-Nd-Ti Microwave Dielectric Ceramics with Distorted Oxygen Octahedrons and High Q × f Value.

ABSTRACT: We investigated the structure and antireduction of Ti⁴⁺ in orthorhombic perovskite Ca_0.61Nd_0.26TiO₃ (CNT) ceramic by doping with three different additives (Cr₂O₃, MnO₂, and SnO₂). The X-ray diffraction patterns showed that the main phase of orthorhombic perovskite was formed in all the samples. In addition, the substitution of M (M = Cr³⁺, Mn⁴⁺, Sn⁴⁺) for Ti⁴⁺ resulted in the oxygen octahedral distortion and changes of order degree of B-site, which was confirmed by Raman spectra. The ε_r and τ_f values were concerned with the average ionicity of B-O bond f _i(B-ave) and the linear expansion coefficient α, respectively. The X-ray photoelectron spectra indicated that three different additives could restrain the reduction of Ti⁴⁺, which was beneficial to the improvement of the Q × f value for CNT ceramic. High Q × f value of 16 123 GHz was obtained in the CNT + 1 mol % Cr₂O₃ ceramic compared with Q × f value of 11 207 GHz in pure CNT ceramic.

SUBMITTER: Xiong Z 

PROVIDER: S-EPMC6644933 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature