Copper calcium titanate--CaCu3Ti4O12 compounds (referred to as CCTO) for perovskite-type cubic crystal structure. Recently reported CaCu3Ti4O12 with anomalous giant dielectric constant (ε ≈ 104-105) and low loss (TG δ ≈ 0.03), particularly over a very wide temperature range (100-400K) dielectric constant value almost unchanged, reflecting dielectric response of high thermal stability. And does not require special manufacturing processes, sintering temperature is low, about 1000 c ~1100 c from top to bottom, is the general nature of the dielectric material is difficult to achieve. The good overall performance, so that it may become high density energy storage, thin film devices (such as MEMS, GB-DRAM), high dielectric capacitors in a series of high-tech areas such as access to a wide range of applications. Cooling but the biggest anomaly is that this kind of material to 100K following sharp decline in dielectric constant (ε ≈ 100), x-ray diffraction (XRD), Raman scattering and neutron diffraction analyses show that even cool to 35K does not observe any long-range structural phase transitions. XRD analysis showed that contrary to the characteristics of ferroelectric domain moment cooperative ordering of explanation. Since there is no convincing explanation of these characteristics. So find out the giant dielectric properties of the material, high thermal stability and mechanism of anomalous decrease of 100K is of great theoretical and practical significance.
