The preparation and characterization of pyroelectric hybrid films containing C.I. Acid Red 29 (chromotrope 2R)

Pyroelectric hybrid materials were prepared from 4,5-dihydroxy-3-(phenyldiazenyl)naphthalene-2,7-disulfonic acid (C.I. Acid Red 29) and Nb or Ta alkoxides via a sol–gel process. The hybrid materials were analyzed and characterized using infrared spectrometry, atom force microscopy and thermal gravimetry differential thermal analysis. The dye was covalently linked to the inorganic network and organic–inorganic hybrid films had excellent pyroelectric character (average pyroelectric coefficient 1.79 × 10−6 C cm−2 K−1) and high thermal stability; no phase separation was observed in the films.