Structures and pyroelectric properties for [111]‐oriented Mn‐doped rhombohedral 0.36PIN‐0.36PMN‐0.28PT crystal

The crystal structures, pyroelectric properties, and thermal stability of [111]‐oriented 0.5 mol% Mn‐doped 0.36Pb(In 1/2 Nb 1/2 )O 3 ‐0.36Pb(Mg 1/3 Nb 2/3 )O 3 ‐0.28PbTiO 3 (Mn‐0.36PIN‐0.36PMN‐0.28PT) ternary single crystal were investigated. The temperature dependence of the Raman spectra and dielectric properties revealed that the crystal exhibited a rhombohedral ( R ) structure at room temperature, and ferroelectric R   →  tetragonal ( T ) and ferroelectric T to paraelectric cubic ( C ) phase transitions at 130 and 175°C respectively. The single crystal had a high remnant polarization of P r  = 38 μC cm –2 and coercive field of E C  = 12 kV cm –1 at room temperature and a frequency of f  = 100 Hz. The values of P r and E C decreased with increasing temperature, exhibiting anomalies near their phase‐transition temperatures, which coincided with changes in the Raman spectra and dielectric properties. Furthermore, at 25°C and f  = 100 Hz, the single crystal had high pyroelectric coefficients of p  = 8.7 × 10 −4  C m −2  K −1 , figures of merit for the current responsivity of F i  = 3.5 × 10 −10  m V −1 , the voltage responsivity of F v  = 0.08 m 2  C −1 , and the detectivity of F d  = 30.1 × 10 −5  Pa −1/2 . These values were weakly dependent on temperature below 120°C. In addition, the room‐temperature pyroelectric coefficients of the ternary single crystal maintain over 83% of the original value at thermal annealing temperatures below 120°C. These outstanding pyroelectric properties, together with high thermal stability, indicate that [111]‐oriented rhombohedral Mn‐0.36PIN‐0.36PMN‐0.28PT ternary single crystal is a new potential candidate for infrared detection applications.