2-Hydroxytryptanthrin and 1-Formyl-2-hydroxytryptanthrin as Fluorescent Metal-ion Sensors and Near-infrared Fluorescent Labeling Reagents

140190C. As can be seen, the leakage current density for all samples is less than 110-5 A/cm2 under an applied field of up to 150 kV/cm, indicating excellent electrical insulation properties. Furthermore, the point at which electrical breakdown occurs shifts to lower electric field as the reaction temperature decreases from 140 to 160°C. The samples produced at 180 and 190°C exhibited strong electrical insulation properties even under a high applied field of up to 300 kV/cm. Figure 7 shows room-temperature P–E hysteresis loops for a sample with a CFO layer synthesized at 180C, and a sample with no CFO layer. Both samples exhibit good hysteresis loop shapes with excellent symmetry. The values of 2Pr (6365 C/cm2) and the coercive field (2Ec: 443445 kV/cm) are the same for both samples within the experimental error. This demonstrates that the nonaqueous sol-gel process is an effective method for introducing fine ferromagnetic particles into the nanospaces between the ferroelectric plates without degrading their electrical properties. The dependence of the room-temperature 2Pr and 2Ec values on the CFO synthesis temperature is shown in Fig. 7(c). 2Pr and 2Ec are seen to be almost constant at 5867 C/cm2 and 421462 kV/cm, respectively, regardless of the reaction temperature. In particular, the 2Pr values are comparable to that for Pb(Zr,Ti)O3, which is currently used in ferroelectric non-volatile memory applications, indicating that the performance level is practical. It can therefore be concluded that the optimal reaction temperature for depositing fine CFO particles on BNEuT/Nb:TiO2 substrates by the non-aqueous sol-gel process is 180°C, from the viewpoints of the structural, magnetization magnetic field, ferroelectric, and leakage current characteristics. 4. CONCLUSION Ferromagnetic CFO thin films were synthesized on (Bi3.25Nd0.65Eu0.10)Ti3O12/Nb:TiO2 substrates at reaction temperatures of 140190C using a non-aqueous sol-gel process. The magnetic properties of the films were measured, and the sample synthesized at 180C was found to exhibit the highest residual magnetization and coercivity of 1.5 emu/g and 134 Oe, respectively. The ferroelectric properties of all samples were similar, with a large remanent polarization of 5867 C/cm2 and a coercive field of 421462 kV/cm, regardless of the reaction temperature. Based on its magnetic and ferroelectric properties, it can be concluded that the sample synthesized at 180C has potential as a practical multiferroic material.