Patterning of ferroelectric β′-Gd2(MoO 4)3 crystal lines on the glass surface by transition metal atom heat processing

Abstract

Lines consisting of ferroelectric β′-Gd2(MoO 4)3 crystals are patterned on the surface of NiO (2 mol%)-doped 21.25Gd2O3·63.75MoO3· 15B2O3 glass by continuous wave (cw) Nd: YAG laser irradiations with a wavelength of λ = 1064 nm, where laser energies absorbed by Ni2+ ions are converted to the local heating of surrounding Ni2+ ions. The surface morphology of crystals in the patterned lines is clarified from confocal scanning laser microscope observations. β′-Gd2(MoO4)3 crystal lines patterned by laser irradiations with a power of 0.73 W and a scanning speed of 2.5 μm/s show a smooth surface with a bump (width: 9 μm, height: 3 μm), and it is suggested from polarized micro-Raman scattering spectra that β′ -Gd2(MoO4) 3 crystals might orient along the laser scanning direction. The present study demonstrates that the transition metal atom heat processing, i.e., a combination of cw Nd:YAG laser and Ni2+ ions, is a novel technique for spatially selected crystallization in rare-earth containing glasses.