Growth and pyroelectric property of 0.2 mol % Fe-doped Pb(Mg[sub ⅓]Nb[sub ⅔])O₃-0.38PbTiO₃ single crystals measured by a dynamic technique

Abstract

To develop a high-performance pyroelectric infrared detector, large-size and high-quality 0.2 mol% Fe-doped Pb(Mg[sub ⅓]Nb[sub ⅔])O₃-0.38PbTiO₃ single crystals have been grown by a modified Bridgman technique with a seed crystal. At 50 Hz, the doped single crystal showed a lower dielectric constant of 310 compared with the pure one. A low dielectric loss of 0.0067 was also obtained by doping with small concentration of iron ions. Piezoelectric coefficient (d[sub 33]) of <001> oriented sample was ~260 pC/N. The pyroelectric properties and their temperature dependence were measured by the dynamic technique. At room temperature, the pyroelectric coefficient and calculated detectivity figure of merit F[sub D] are 568 µC/m² K and 53 µPa[sup -½], respectively. The values of current response figure of merit F[sub i] and voltage response figure of merit F[sub v] are 227.2 pm/V and 0.083 m²/C, respectively. These excellent pyroelectric properties as well as being able to produce large-size and high-quality single crystals make this kind of single crystal very promising for high-performance infrared detectors and other pyroelectric applications.