Ordered YBCO sub-micron array structures induced by pulsed femtosecond laser irradiation.
We report on the formation of organized sub-micron YBa(2)Cu(3)O(7) (YBCO) dots induced by irradiating femtosecond laser pulses on YBCO films prepared by pulse laser deposition with fluence in the range of 0.21 approximately 0.53 J/cm(2). The morphology of the YBCO film surface depends strongly on the laser fluences irradiated. At lower laser fluence (approximately 0.21 J/cm(2)) the morphology was pattern of periodic ripples with sub-micrometer spacing. Slightly increasing the laser fluence to 0.26 J/cm(2) changes the pattern into organized sub-micron dots with diameters ranging from 100 nm to 800 nm and height of 150 nm. Further increase of the laser fluence to over 0.32 J/cm(2), however, appeared to result in massive melting and led to irregular morphology. The mechanism and the implications of the current findings will be discussed. Arrays of YBCO sub-micron dots with T(c) = 89.7 K were obtained.
Luo
C W
CW
Department of Electrophysics, National Chiao-Tung University, Hsinchu, Taiwan, ROC. cwluo@mail.nctu.edu.tw
Lee
C C
CC
Li
C H
CH
Shih
H C
HC
Chen
Y-J
YJ
Hsieh
C C
CC
Su
C H
CH
Tzeng
W Y
WY
Wu
K H
KH
Juang
J Y
JY
Uen
T M
TM
Chen
S P
SP
Lin
J-Y
JY
Kobayashi
T
T
D007834:Lasers; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D011829:Radiation Dosage