Lee, Sung-Yun Kim, Young-Hwan Choi, Kyoung Jin Jung, Sung-Mok Yoo, Sang-Im 2024-01-20T18:35:03Z 2024-01-20T18:35:03Z 2021-09-05 2010-08-02 0040-6090 https://pubs.kist.re.kr/handle/201004/131186 We investigated the effects of post-deposition cooling conditions on the surface morphologies and dielectric properties of CaCu3Ti4O12 (CCTO) thin films grown by pulsed-laser deposition on Pt/TiO2/SiO2/Si substrates. CCTO thin films cooled under the typical cooling parameters, i.e., slow cooling (3 degrees C/min) at high oxygen pressure (66 kPa) showed a severe segregation of nanoparticles near the grain boundaries, which was identified to be copper oxide from electron probe micro analyzer mapping. On the other hand, we could not observe any segregation on the film surface when the samples were cooled fast (similar to 20 degrees C/min) at relatively low oxygen pressure (100 Pa). The dielectric constant, epsilon(r). of CCTO thin films deposited at 750 degrees C with severe surface segregation (epsilon(r) similar to 750 at 10 kHz) was found to be much lower than that (epsilon(r) similar to 2000 at 10 kHz) of CCTO thin films with smooth surface. As the copper-oxide segregation becomes more serious, which preferentially occurs at relatively high ambient oxygen pressure and temperature, the degradation in the dielectric properties of CCTO films becomes larger. The variation of dielectric constant of CCTO films with no copper-oxide segregation could be related to the presence of an impurity phase at grain boundaries. (C) 2010 Elsevier B.V. All rights reserved. English ELSEVIER SCIENCE SA CONSTANT Effect of copper-oxide segregation on the dielectric properties of CaCu3Ti4O12 thin films fabricated by pulsed-laser deposition Article 10.1016/j.tsf.2010.05.048 1 THIN SOLID FILMS, v.518, no.20, pp.5711 - 5714 THIN SOLID FILMS 518 20 5711 5714 scie scopus 000280541400022 2-s2.0-77955420729 Materials Science, Multidisciplinary Materials Science, Coatings & Films Physics, Applied Physics, Condensed Matter Materials Science Physics Article CONSTANT CaCu3Ti4O12 (CCTO) Pulsed laser deposition Dielectric constant and loss Copper-oxide segregation