TY - JOUR
T1 - Ultraviolet pulsed laser crystallization of Ba0.8Sr0.2TiO3 films on LaNiO3-coated silicon substrates
AU - Queraltó, Albert
AU - Pérez Del Pino, Angel
AU - De La Mata, María
AU - Tristany, Mar
AU - Obradors, Xavier
AU - Puig, Teresa
AU - Trolier-McKinstry, Susan
N1 - Funding Information:
This work was financed by the Ministry of Economy and Competitiveness under the projects MAT2011-28874-C02-01 , MAT2014-51778-C2-1-R , ENE2014-56109-C3-3-R and Consolider Nanoselect CSD2007-00041 , and by Generalitat de Catalunya ( 2015 SGR 753 and Xarmae). AQ and MdlM are also grateful for JAE-Predoc fellowship (E-08-2012-1321248) and European Social Fund (E-08-2013-1028356) program. Fruitful discussions with Dr. Susagna Ricart for solution synthesis are also acknowledged.
Publisher Copyright:
© 2015 Elsevier Ltd and Techna Group S.r.l.
PY - 2016/2/15
Y1 - 2016/2/15
N2 - In this work, Ba0.8Sr0.2TiO3 (BST) films on LaNiO3-buffered SiO2/Si (LNO/SiO2/Si) substrates were crystallized by pulsed laser irradiation. Solution-derived amorphous barium-strontium-titanate precursor layers were crystallized with a KrF excimer laser in oxygen ambient at fluences ranging from 50 to 75 mJ cm-2. With the substrate temperature set to 500 °C, the number of pulses and film thickness were varied until high-quality crystallinity could be achieved. It was found that films with a thickness of 40 nm are fully crystallized with a uniaxial {00l} orientation which is predetermined by the LaNiO3 orientation. On the other hand, for 160 nm thick films, crystallization was observed after 12,000 pulses in the 70 nm close to the surface, while the rest of the film remained amorphous. The large temperature difference between the film surface and interface due to the low thermal conductivity of the amorphous BST is suggested as the origin of this behavior. Films thicker than 80 nm cracked on crystallization due to the stress caused by the different thermal expansion coefficients of film and substrate, as well as the large temperature variations within the BST film.
AB - In this work, Ba0.8Sr0.2TiO3 (BST) films on LaNiO3-buffered SiO2/Si (LNO/SiO2/Si) substrates were crystallized by pulsed laser irradiation. Solution-derived amorphous barium-strontium-titanate precursor layers were crystallized with a KrF excimer laser in oxygen ambient at fluences ranging from 50 to 75 mJ cm-2. With the substrate temperature set to 500 °C, the number of pulses and film thickness were varied until high-quality crystallinity could be achieved. It was found that films with a thickness of 40 nm are fully crystallized with a uniaxial {00l} orientation which is predetermined by the LaNiO3 orientation. On the other hand, for 160 nm thick films, crystallization was observed after 12,000 pulses in the 70 nm close to the surface, while the rest of the film remained amorphous. The large temperature difference between the film surface and interface due to the low thermal conductivity of the amorphous BST is suggested as the origin of this behavior. Films thicker than 80 nm cracked on crystallization due to the stress caused by the different thermal expansion coefficients of film and substrate, as well as the large temperature variations within the BST film.
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U2 - 10.1016/j.ceramint.2015.11.075
DO - 10.1016/j.ceramint.2015.11.075
M3 - Article
AN - SCOPUS:84952062161
SN - 0272-8842
VL - 42
SP - 4039
EP - 4047
JO - Ceramics International
JF - Ceramics International
IS - 3
ER -