Patterning and Characterization of Ferroelectric Crystal Lines at the Glass Surface by Laser-Induced Crystallization

A technique for the patterning of ferroelectric crystal lines such as Sr
_0.5
Ba
_0.5
Nb
₂
O
₆
, LiNbO
₃
, β'-Gd
₂
(MoO
₄
)
₃
at the glass surface has been developed, i.e., transition metal atom heat processing, in which continuous wave lasers such as Nd:YAG (wavelength: λ=1064 nm) are irradiated to the glasses containing transition metal (TM: Cu
²⁺
, Ni
²⁺
) ions. The absorbed laser results in local heating of glass, consequently inducting crystallization. By scanning laser (power: < 1W) at constant speeds such as 10 μm/s, ferroelectric crystal lines are written successfully at the glass surface. The surface morphology and orientation of crystals in the lines are clarified from confocal laser microscope observations and polarized micro-Raman scattering spectra measurements. In some glasses, the patterning of crystal lines consisting of oriented ferroelectrics is possible.