Affiliation:
1. Department of Electrical Engineering and Automation, Luoyang Institute of Science and Technology, Luoyang 471023, China
2. School of Microelectronics, Tianjin University, Tianjin 300072, China
Abstract
Ferroelectric varactors should have high tunability at low permittivity and a working electric field to obtain better impedance matching and stable tunability. In this work, (Ba0.91Ca0.09)(SnxZr0.2−xTi0.8)O3-2 mol% CuO-1 mol% Li2CO3 (abbreviated as BCSZT100x, x = 0.05, 0.10, 0.15 and 0.20, respectively) are prepared to achieve high tunability at low permittivity and a working electric field. The tunable mechanisms are investigated based on crystal structure, micro-morphology and the permittivity-temperature spectrum. The results show that the shrink of oxygen octahedron and weaker interaction force between Sn4+ and O2− make BCSZT5 ceramic have a higher tunability value of 26.55% at low permittivity (1913) and a working electric field (7.3 kV/cm). The tunability value of BCSZT5 ceramic increases by 58%, while its permittivity decreases by 25%, compared with x = 0. Those advantages make BCSZT5 ceramic have substantial application prospects in varactors.
Funder
National Natural Science Foundation of China
Science and Technology Project of Henan Province
Subject
General Materials Science