A new method for modification of Ca2+ doped PbTiO3 humidity sensitive nano-film: Preparation, humidity sensitivity and structure of K+-modified thin film

作者：Wang ZM^*; Zuo X; Han JX; Liu JB; Zhang YX

来源：Acta Chimica Sinica, 2003, 61(11): 1792-1796.

• K+ modified-Ca2+ doping
• PbTiO3 nanofilm
• property of resistance-relative humidity
• structure characterization

In order to increase the humidity sensitivity of PbTiO3, using Ti(O-n-Bu)(4)(or (n-BuO)(4)Ti), Pb(OAc)(2) and Ca(OAc)(2) as the starting materials, K+-modified and Ca2+-doped PbTiO3 nano-film (K+-Ca-x Pb1-xTiO3, abbreviated as K-CPT) was prepared by sol-gel method, namely, spin-coating sol on alpha-Al2O3 substrate plated with Ag-Pd alloy interdigital electrode and then sintered at 850 degreesC/1 h for crystallization. Its property of resistance-relative humidity was tested at the constant temperature of (20 +/- 0.1)degreesC, and compared with pure PbTiO3 (PT), Ca2+-doped PbTiO3(CPT) and Li+-modified Ca2+-doped PbTiO3 nano-film (Li+-CaxPb1-xTiO3, Li-CPT for short). Process parameters were investigated by orthogonal design. The results indicated that the film prepared with formula of x = 0.35 and K+ content= 1.0% (K/Ti, mol/mol), and sintered at 850 degreesC/1 h, displayed the sensitivity S = 3.3 x 10(3) in the range of RH = 8.0% similar to 93.6%, response time tau = 15 s and humidity hysteresisless than or equal to +/- 2%; the total sensitivity Scongruent to10(4) in the extrapolation range of RH = 0.0% similar to 100.0%. The film was characterized by XRD, SEM and TEM, which showed the tetragonal nano-polycrystalline with 10 nm of grain size and electric domain structure reticulated pores and obvious grain boundary like island with 4 mum x 5 mum area.

• 出版日期2003-11
• 单位黑龙江大学