BaTiO3∶Mn0.006Smx(x=0.001, 0.002, 0.003, 0.004, 0.006 respectively) ceramics were prepared by using sol-gel method and their resistivities at different temperatures were measured. The results showed that Mn element m...BaTiO3∶Mn0.006Smx(x=0.001, 0.002, 0.003, 0.004, 0.006 respectively) ceramics were prepared by using sol-gel method and their resistivities at different temperatures were measured. The results showed that Mn element may enhance the PTC characteristics of BaTiO3 ceramics. But the doped Mn element deteriorated the room temperature resistivities of the modified BaTiO3 ceramics which were greater than 105 Ω·m. Then, rare earth element Sm was penetrated into BaTiO3∶Mn0.06Smx ceramics in gaseous state, which largely decreased the room temperature resistivity to 3.20 Ω·m, and appeared as a NTC effect instead of PTC effect. The forming mechanism of NTC effect was explored through analyses of SEM and electric properties of Sm-penetrated BaTiO3∶Mn0.006Smx ceramics.展开更多
为了开发高性能聚合物基NTC热敏电阻,将石墨烯均匀地分散在868环氧树脂聚合物基体中并固化成型,制备得到一种具有负温度系数(Negative Temperature Coefficient,NTC)的环氧树脂/石墨烯复合材料,研究了石墨烯含量、固化工艺对复合材料体...为了开发高性能聚合物基NTC热敏电阻,将石墨烯均匀地分散在868环氧树脂聚合物基体中并固化成型,制备得到一种具有负温度系数(Negative Temperature Coefficient,NTC)的环氧树脂/石墨烯复合材料,研究了石墨烯含量、固化工艺对复合材料体积电阻率及NTC强度的影响,并考察了复合材料的稳定性和附着力。结果表明,石墨烯质量分数为5%的样品,当固化温度为40℃,时间为9 h时,在50℃测试条件下,其体积电阻率为9.32×10^(6)Ω·cm,当测试温度升高到100℃,体积电阻率下降为4.35×10^(3)Ω·cm;同时,NTC强度最高可达到3.33,并且其在PET膜上表现出优异的附着力;经过3次重复加热测试后石墨烯在基体内部发生轻微的不可逆变化,初始体积电阻率有所降低,后续导电结构趋于稳定,并表现出优异的循环稳定性。本研究为聚合物基NTC热敏电阻的研究提供一定理论基础,有助于推动其在电子、通信、新型储能等行业的应用。展开更多
Y^3＋-doped （Bi 1/2 Na 1/2） TiO 3-CaTiO 3-BaTiO 3 （BNCBT） positive temperature coefficient of resistivity （PTCR） ceramics sintered in air atmosphere were investigated in this study. （Bi 1/2 Na 1/2） TiO 3 （BNT...Y^3＋-doped （Bi 1/2 Na 1/2） TiO 3-CaTiO 3-BaTiO 3 （BNCBT） positive temperature coefficient of resistivity （PTCR） ceramics sintered in air atmosphere were investigated in this study. （Bi 1/2 Na 1/2） TiO 3 （BNT） component can remarkably increase the onset temperature T c of PTCR ceramics with the expense of the resistivity R 25 increase. CaTiO 3 （9–27 mol%） component can decrease the resistivity, and adjust the effects of BNT phase on the T c point. For the sample containing 3 mol% CaTiO 3 , T c raises from 122 ℃ to 153 ℃ when only 0.6 mol% BNT added, while for the ones with higher CaTiO 3 content （9–27 mol%）, T c is only increased by a rate of 8–9℃/1.0 mol% BNT. The effects of BNT and CaTiO 3 components on R25/Rmin （negative temperature coefficient effect） are also discussed.展开更多
负温度系数(negative temperature coefficient,NTC)热敏电阻器由于在窄温区内具有极高的灵敏度,在海洋领域中有着广泛的应用,但深海应用中固有的高静水压力,对器件的测温准确度造成不利影响。为了更好地认识这种现象,以珠状NTC热敏电...负温度系数(negative temperature coefficient,NTC)热敏电阻器由于在窄温区内具有极高的灵敏度,在海洋领域中有着广泛的应用,但深海应用中固有的高静水压力,对器件的测温准确度造成不利影响。为了更好地认识这种现象,以珠状NTC热敏电阻器为研究对象,利用海洋环境高压模拟装置,开展了静水压力作用对器件电学特性影响的研究,固定环境温度25℃和0℃,压力范围0~60 MPa,步长5 MPa。结果显示,随着静水压力的增大,NTC热敏电阻器的电阻值减小;环境温度25℃和0℃时,5~60 MPa的静水压力造成的漂移分别为-0.11%~-2.81%、-0.19%~-2.78%,等效于温度漂移分别为0.024~0.624℃、0.036~0.535℃。这为热敏电阻器在深海温度准确测量的提升提供了指引,有利于在海洋测温领域中更好的应用。展开更多
文摘BaTiO3∶Mn0.006Smx(x=0.001, 0.002, 0.003, 0.004, 0.006 respectively) ceramics were prepared by using sol-gel method and their resistivities at different temperatures were measured. The results showed that Mn element may enhance the PTC characteristics of BaTiO3 ceramics. But the doped Mn element deteriorated the room temperature resistivities of the modified BaTiO3 ceramics which were greater than 105 Ω·m. Then, rare earth element Sm was penetrated into BaTiO3∶Mn0.06Smx ceramics in gaseous state, which largely decreased the room temperature resistivity to 3.20 Ω·m, and appeared as a NTC effect instead of PTC effect. The forming mechanism of NTC effect was explored through analyses of SEM and electric properties of Sm-penetrated BaTiO3∶Mn0.006Smx ceramics.
文摘为了开发高性能聚合物基NTC热敏电阻,将石墨烯均匀地分散在868环氧树脂聚合物基体中并固化成型,制备得到一种具有负温度系数(Negative Temperature Coefficient,NTC)的环氧树脂/石墨烯复合材料,研究了石墨烯含量、固化工艺对复合材料体积电阻率及NTC强度的影响,并考察了复合材料的稳定性和附着力。结果表明,石墨烯质量分数为5%的样品,当固化温度为40℃,时间为9 h时,在50℃测试条件下,其体积电阻率为9.32×10^(6)Ω·cm,当测试温度升高到100℃,体积电阻率下降为4.35×10^(3)Ω·cm;同时,NTC强度最高可达到3.33,并且其在PET膜上表现出优异的附着力;经过3次重复加热测试后石墨烯在基体内部发生轻微的不可逆变化,初始体积电阻率有所降低,后续导电结构趋于稳定,并表现出优异的循环稳定性。本研究为聚合物基NTC热敏电阻的研究提供一定理论基础,有助于推动其在电子、通信、新型储能等行业的应用。
基金Project supported by the SPAT of Shanghai Committee of Chinese People's Political Consultative Conference and Shanghai Education Development Foundation (Grant No.2008012)
文摘Y^3＋-doped （Bi 1/2 Na 1/2） TiO 3-CaTiO 3-BaTiO 3 （BNCBT） positive temperature coefficient of resistivity （PTCR） ceramics sintered in air atmosphere were investigated in this study. （Bi 1/2 Na 1/2） TiO 3 （BNT） component can remarkably increase the onset temperature T c of PTCR ceramics with the expense of the resistivity R 25 increase. CaTiO 3 （9–27 mol%） component can decrease the resistivity, and adjust the effects of BNT phase on the T c point. For the sample containing 3 mol% CaTiO 3 , T c raises from 122 ℃ to 153 ℃ when only 0.6 mol% BNT added, while for the ones with higher CaTiO 3 content （9–27 mol%）, T c is only increased by a rate of 8–9℃/1.0 mol% BNT. The effects of BNT and CaTiO 3 components on R25/Rmin （negative temperature coefficient effect） are also discussed.
