Controlling the preferential orientation in sol-gel prepared CaCu3Ti4O12 thin films by LaAlO3 and NdGaO3 substrates

DITSAYUT PHOKHARATKUL; SURIYONG PONGPAIBOONKUL; ANURAT WISITSORAAT; BUNDIT PUTASAENG; SATREERAT K. HODAK; YUMAIRAH KASA; JOSE H. HODAK

APPLIED SURFACE SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 385 p. 424 - 432

0169-4332

Researchers have paid considerable attention to CaCu3Ti4O12 (CCTO) due to the colossaldielectric constant over a wide range of frequency and temperature. Despite of the growingnumber of works dealing with CCTO, there have been few studies of the role played by thesubstrate in inducing structural and dielectric effects of this material. In this work, highlyorientedCCTO thin films have been deposited on LaAlO3(100), NdGaO3(100) andNdGaO3(110) substrates using a sol-gel method. These single crystal substrates were chosen interms of small lattice mismatch between CCTO and the substrate. The X-ray diffraction patternsshowed that the CCTO film layers grow with different orientations depending upon the substrateused. We show that the preferred orientation of CCTO thin films can be manipulated to a highdegree by growing it on specific crystal planes of the substrates without the use of buffer layers.Colossal dielectric constants are observed in our films which appear to correlate with the filmcrystallinity and preferred orientation.