Growth and piezoelectric properties of TmCOB single crystals

New rare-earth oxyborate crystals TmCOB were grown by using the Czochralski method. The piezoelectric coefficients for TmCOB were determined to be on the order of d
₁₁
=1.7, d
₁₂
=3.8, d
₁₃
=-4.2, d
₁₅
=-0.92, d
₂₄
=4.9, d
₂₆
=7.8, d
₃₁
=-0.75, d
₃₂
=-2.4, d
₃₃
=2.2 and d
₃₅
=-5.2 pC/N. The temperature dependence of electro-elastic propertieswereinvestigated from 20 to 900°C, where the temperature coefficients of the elastic compliances (s
^E
₂₂
, s
^E
₃₃
and s
^E
₆₆
) were foundto be ranged from 146 to223 ppm/°C for TmCOB crystals. Particularly, the electromechanical factor k
₁₂
was evaluated to be on the order of 15.4% at room temperature, with a small variation <;5.4% in the temperature range of 20-900°C. Moreover, the TmCOB crystals were obtained to possess high piezoelectric coefficientd
₂₆
being 7.8 pC/N, 3-4 times that of quartz, and showing a minimal variation of -12.9% over the test temperature range, potential for high temperature piezoelectric applications.