Heat treatment effect with the electrode contact of CaCu3Ti4O12

Abstract

ABSTRACT

CaCu₃Ti₄O₁₂ (CCTO) has attracted a great attention for electronic devices miniaturization due to its very high dielectric constant properties at a wide range of frequency and nearly constant over broad temperature range. The origins of the giant dielectric constant have been speculated from electrical heterogeneous of interior elements of the CCTO ceramics. Four origins were suggested contributed to the electrical heterogeneous. In this study heat treatment were done with the electrode contact in Argon gas environment and the electrical properties over very wide frequency of CCTO ceramics were investigated. Cylindrical CCTO pellets samples were prepared by solid state reaction method and single phase of XRD pattern was obtained after sintering processes. Electrical impedance responds were measured at frequency from 100 Hz to 1 GHz for the samples for untreated and heat treated at 200ºC, 250ºC, 300ºC, 350ºC and 400ºC of CCTO. Improvement to the dielectric constant can be seen for 350ºC and 400ºC samples and dielectric loss were improved for 200ºC and 300ºC samples for overall frequency. The variations were discussed based on oxygen deficiency content and resistivity of the elements inside of CCTO structure.

ABSTRAK

CaCu₃Ti₄O₁₂ (CCTO) telah menarik perhatian tinggi untuk pengecilan peranti elektronik disebabkan sifat pemalar dielektrik yang sangat tinggi pada julat frekuensi yang luas dan hampir malar dalam julat suhu yang luas. Asal-usul pemalar dielektrik tinggi telah dispekulasikan daripada ketidakseragaman sifat elektrik unsur-unsur dalaman seramik CCTO. Empat asal-usul telah dicadangkan yang menyumbang kepada sigat heterogen elektrik tersebut. Dalam kajian ini, rawatan haba telah dilakukan bersama dengan elektrod dalam persekitaran gas Argon dan sifat elektrik terhadap frekuensi luas seramik CCTO telah kenalpasti. Sampel silinder CCTO telah disediakan oleh kaedah tindak balas keadaan pepejal dan fasa tunggal corak pembelauan XRD telah diperolehi selepas proses pensinteran. Respon elektrik impedan telah diukur pada frekuensi 100Hz hingga 1GHz untuk sampel tidak dirawat dan dirawat haba pada 200º C, 250º C, 300º C, 350º C dan 400º C daripada CCTO. Peningkatan kepada pemalar dielektrik boleh dilihat pada sampel 350º C dan 400º C dan kehilangan dielektrik telah bertambah baik untuk sampel 200º C dan 300ºC bagi keseluruhan frekuensi. Variasi tersebut telah dibincangkan berdasarkan kandungan kekurangan oksigen dan kerintangan elemen-elemen di dalam struktur CCTO.