钛酸钡基电介质陶瓷因具有良好的介电和正温度系数特性已被广泛应用于科技、工业以及日常生活中,在新兴领域的需求下,开发具有低居里温度和高常温电阻率特性的电介质陶瓷材料具有重要意义。因此,采用固相法制备了不同掺杂浓度氧化钇(Y_(...钛酸钡基电介质陶瓷因具有良好的介电和正温度系数特性已被广泛应用于科技、工业以及日常生活中,在新兴领域的需求下,开发具有低居里温度和高常温电阻率特性的电介质陶瓷材料具有重要意义。因此,采用固相法制备了不同掺杂浓度氧化钇(Y_(2)O_(3))的钛酸锶钡(Ba_(0.7)Sr_(0.3)TiO_(3),BST),正温度系数(positive temperature coefficient,PTC)陶瓷材料,通过X射线衍射和扫描电镜测试了试样的理化特性,利用宽频介电谱仪和电阻率–温度测量系统分别获得了试样的介电–温度特性和电阻率–温度特性,并构建了四象限模型分析钇(Y)对材料介电–温度特性和电阻率–温度特性的影响机理。研究表明:随Y_(2)O_(3)含量的增大,介电常数和居里温度均呈先增大后减小的趋势,而常温电阻率呈现相反的变化趋势。0.0008 mol的Y_(2)O_(3)掺杂可大幅提高BST材料相对介电常数(>105)且具有较低的居里温度(34.1℃)和较大的常温电阻率(5.6×106Ω·cm)。实现了低居里温度和高电阻率特性的协同调控,拓宽了PTC材料的应用范围。展开更多
Cavity perturbation method was used to determine the dielectric properties （ε′,ε″, and tanδ） of zinc oxide dust in different apparent densities. The process was conducted to study the microwave-absorption prope...Cavity perturbation method was used to determine the dielectric properties （ε′,ε″, and tanδ） of zinc oxide dust in different apparent densities. The process was conducted to study the microwave-absorption properties of zinc oxide dust and the feasibility of microwave roasting zinc oxide dust to remove fluorine and chlorine. The dielectric constant, dielectric loss, and loss tangent were proportional to the apparent density of zinc oxide dust. The effects of sample mass and microwave power on the temperature increase characteristics under the microwave field were also studied. The results show that the apparent heating rate of the zinc oxide dust increases with the increase in microwave roasting power and decreases with the increase in the sample mass. The temperature of the samples reaches approximately 800 ＆#176;C after microwave treatment for 8 min, which indicates that the zinc oxide dust has strong microwave-absorption ability.展开更多
文摘钛酸钡基电介质陶瓷因具有良好的介电和正温度系数特性已被广泛应用于科技、工业以及日常生活中,在新兴领域的需求下,开发具有低居里温度和高常温电阻率特性的电介质陶瓷材料具有重要意义。因此,采用固相法制备了不同掺杂浓度氧化钇(Y_(2)O_(3))的钛酸锶钡(Ba_(0.7)Sr_(0.3)TiO_(3),BST),正温度系数(positive temperature coefficient,PTC)陶瓷材料,通过X射线衍射和扫描电镜测试了试样的理化特性,利用宽频介电谱仪和电阻率–温度测量系统分别获得了试样的介电–温度特性和电阻率–温度特性,并构建了四象限模型分析钇(Y)对材料介电–温度特性和电阻率–温度特性的影响机理。研究表明:随Y_(2)O_(3)含量的增大,介电常数和居里温度均呈先增大后减小的趋势,而常温电阻率呈现相反的变化趋势。0.0008 mol的Y_(2)O_(3)掺杂可大幅提高BST材料相对介电常数(>105)且具有较低的居里温度(34.1℃)和较大的常温电阻率(5.6×106Ω·cm)。实现了低居里温度和高电阻率特性的协同调控,拓宽了PTC材料的应用范围。
基金Project(51104073)supported by the National Natural Science Foundation of ChinaProject(2014CB643404)supported by the National Basic Research Program of China+1 种基金Project(2013AA064003)supported by the Hi-tech Research and Development Program of ChinaProject(2012HB008)supported by the Yunnan Provincial Young Academic Technology Leader Reserve Talents,China
文摘Cavity perturbation method was used to determine the dielectric properties （ε′,ε″, and tanδ） of zinc oxide dust in different apparent densities. The process was conducted to study the microwave-absorption properties of zinc oxide dust and the feasibility of microwave roasting zinc oxide dust to remove fluorine and chlorine. The dielectric constant, dielectric loss, and loss tangent were proportional to the apparent density of zinc oxide dust. The effects of sample mass and microwave power on the temperature increase characteristics under the microwave field were also studied. The results show that the apparent heating rate of the zinc oxide dust increases with the increase in microwave roasting power and decreases with the increase in the sample mass. The temperature of the samples reaches approximately 800 ＆#176;C after microwave treatment for 8 min, which indicates that the zinc oxide dust has strong microwave-absorption ability.
