Abstract. Pyroelectric properties of phosphoric acid (H₃PO₄)-doped triglycine sulfate (TGSP) single crystals grown from solutions containing 0.1–0.5 mol of H₃PO₄ have been studied. Incorporation of H₃PO₄ into the crystal lattice is found to induce an internal bias field (E_b) and is observed through the presence of a sustained polarization and pyroelectricity beyond the transition temperature. The internal bias field has been estimated theoretically by fitting the experimentally measured data on temperature dependence of the pyroelectric coefficient (λ), dielectric constant (ε') and polarization (P). A high E_b value in the range 9 × 10³–15.5 × 10⁴ V m⁻¹ is obtained for crystals grown with 0.1–0.5 mol of H₃PO₄ in the solution, and a specific concentration of 0.2–0.25 mol of H₃PO₄ in the solution during crystal growth is found to be optimum for a high figure of merit for detectivity, F_d = 428 µC m⁻² K⁻¹.

Print publication: Issue 24 (21 December 2003)
Received 29 May 2003
Published 25 November 2003