Zero Temperature Compensated Microwave Dielectric Properties of Ca_0.8Sr_0.2TiO₃–Li_0.5Ln_0.5TiO₃ System

Abstract

The microwave dielectric properties of (1 – x) Ca _0.8 Sr _0.2 TiO ₃ + xLi _0.5 Ln _0.5 TiO ₃ (CST-LLT) (x = 0–1.0) (Ln: Nd, Sm) system have been investigated. The dielectric constant (ε _r ) decreased with x increasing. The temperature coefficient of resonant frequency (τ _f ) decreased almost linearly from high positive values to negative values with the increase of x. A near zero τ _f was achieved at x = 0.87 for Nd and x = 0.81 for Sm ions, respectively. Optimized microwave dielectric properties (ε _r = 111.6; Q × f = 2013 GHz; τ _f = – 2.75 ppm/°C) of CST-LNT and (ε _r = 95; Q × f = 3303 GHz; τ _f = – 1.8 ppm/°C) of CST-LST were estimated at x = 0.87 and x = 0.81 respectively.

Keywords:

• Perovskite structure
• LLT systems
• Microwave dielectric ceramics
• Temperature coefficient of resonant frequency