Strontium barium titanate Bragg mirror and its preparing method

[0018] Example 1

[0019] The preparation of a solution with a barium-strontium ratio of 90 / 10: Dissolve 2.7864g barium acetate, 0.2603g strontium acetate, and 0.65g polyvinylpyrrolidone in 30ml heated glacial acetic acid, then add about 2ml caproylacetone, stir and allow to cool Finally, add 4.1670ml titanium n-butoxide and continue to stir for 2-3 hours, add a small amount of distilled water to dilute, and filter to obtain a clear and transparent barium strontium titanate precursor solution with a molar concentration of about 0.3M / L. The solution will not deteriorate for a long time (more than half a year).

[0020] Preparation of barium strontium titanate Bragg reflective film: using the sol-gel coating process, with a spinning speed of 4000 revolutions per minute, within 60 seconds, two times (interval 20 seconds) will be prepared The barium strontium titanate precursor solution was dropped onto the rotating strontium titanate single crystal substrate, and the barium strontiu

[0021] Example 2

[0022] The preparation of a solution with a barium-strontium ratio of 70 / 30: Dissolve 2.1672g barium acetate, 0.7808g strontium acetate, and 0.65g polyvinylpyrrolidone in 30ml heated glacial acetic acid, then add about 2ml caproylacetone, stir and allow to cool Finally, add 4.1670ml titanium n-butoxide and continue stirring for 2-3 hours, add a small amount of distilled water and filter to obtain a clear and transparent barium strontium titanate precursor solution with a molar concentration of about 0.3M / L.

[0023] With the spinning speed of 3000 revolutions per minute, in 60 seconds, the prepared barium strontium titanate precursor solution was dropped on the rotating strontium titanate single crystal substrate in two intervals of 20 seconds. On top, spin-coated barium strontium titanate film layer; then put the spin-coated film into a rapid annealing furnace, heat treatment at 180℃, 400℃ and 750℃ for 5 minutes, 5 minutes and 10 minutes respectively; repeat 1