Electrical Properties and DC Conductivity of Phosphoric Acid Doped TGS Single Crystals

Properties of phosphoric acid (H₃PO₄) doped triglycine sulfate (TGSP) grown from aqueous solutions containing 0.1 to 0.5 moles of H₃PO₄ have been investigated. Composition analysis indicates a very low incorporation of phosphoric acid in the crystal lattice. Large sized crystals of dimension (70 mm × 40 mm × 25 mm) suitable for IR detector are obtained with 0.2 moles of H₃PO₄ in solution. The presence of both zwitter and glycinium ions in TGSP is explained through FT-IR analysis. The dielectric dispersion of TGSP crystals in the frequency range from 100 Hz to 100 KHz, and in the temperature range 27 to 65°C has been analyzed. The increased dielectric dispersion in TGSP crystals is found to be related to the increase in dc conductivity, and the increased domain boundary relaxation time. Doped crystals show a broad transition and suppressed value of peak dielectric constant.

Keywords:

• Singe crystals
• dielectric properties
• DC conductivity
• FT-IR

Acknowledgments

Paper originally presented at AMF-4, Bangalore, India, December 12-15, 2003.