共沉淀法对yYCr_(x)Mn_(1-x)O_(3)-(1-y)Y_(2)O_(3)体系特征值的影响  

Effect of co‐precipitation method on characteristic values of yYCr_(x)Mn_(1-x)O_(3)−(1-y)Y_(2)O_(3) system

作　　者：王典 谢光远[1] 吕俊涛 李湾湾 WANG Dian;XIE Guangyuan;LYU Juntao;LI Wanwan(School of Materials and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学材料与冶金学院,湖北武汉430081

出　　处：《中国粉体技术》2025年第2期105-111,共7页China Powder Science and Technology

基　　金：国家自然科学基金项目,编号:51904213。

摘　　要：【目的】通过调控Cr、Mn原子的掺杂比(x)和YCr_(x)Mn_(1-x)O_(3)相的物质的量比(y),研究共沉淀法对yYCr_(x)Mn_(1-x)O_(3)-(1-y)Y_(2)O_(3)体系产物特征值的影响。【方法】采用固相法制备8组不同x、y配比的稀土钙钛矿负温度系数(negative temperature coefficient,NTC)热敏电阻,通过X射线衍射(X-ray diffraction,XRD)和电性能分析粗选出性能较优异组(x=0.3,y=0.6),在此基础上,对yYCr_(0.3)Mn_(0.7)O_(3)-(1-y)Y_(2)O_(3)体系用化学共沉淀法制备4组不同y值的粒径更小、均匀性更高的粉体,通过煅烧压片得到NTC陶瓷,探讨共沉淀法对产物性能的影响。【结果】在共沉淀法制备的yYCr_(0.3)Mn_(0.7)O_(3)-(1-y)Y_(2)O_(3)体系中,当y≥0.6时,热敏常数B25/85≥2180 K,活化能为Ea≥0.19 eV;通过增加Mn4+的质量分数,降低Y_(2)O_(3)的质量分数,可以增加YCr_(0.3)Mn_(0.7)O_(3)相,提高电阻对温度改变的敏感度,即热敏常数B。【结论】在共沉淀法制备的yYCr_(0.3)Mn_(0.7)O_(3)-(1-y)Y_(2)O_(3)体系中,通过调控x和y,可以降低材料的电阻率。Objective Negative temperature coefficient(NTC)thermistors are widely used in fields such as automotive electronics,house-hold appliances,aerospace,and medical equipment due to their ability to measure temperature,provide temperature compensa-tion,and suppress inrush current.To enhance the resistivity(ρ)and reduce the thermal sensitivity constant(B)of ceramic NTCs,this study investigates the effect of the co-precipitation method on the characteristic values of the yYCr_(x)Mn_(1-x)O_(3)-(1-y)Y_(2)O_(3) system by adjusting the x and y ratios.Methods Initially,during the preparation stage of the solid-phase method,eight different ratios of x and y were precisely selected to prepare rare-earth perovskite negative temperature coefficient thermistor(NTC)samples according to the yYCrₓMn₁₋ₓO₃-(1-y)Y_(2)O_(3)system.The raw materials Y_(2)O_(3),Cr_(2)O_(3),and MnCO₃were accurately weighed according to each ratio.After steps such as grinding and mixing,they were pressed into shape and then sintered in a high-temperature furnace under specific tem-perature and time conditions.Subsequently,the crystal structure and phase composition of the samples were analyzed using X-ray diffraction(XRD)technology.Meanwhile,electrical performance analysis was carried out to comprehensively evaluate parameters such as the direct current resistivity,thermistor constant B₂₅/₈₅,and activation energy Eₐof the samples.After careful comparison,the optimal ratio(x=0.3,y=0.6)was finally selected.On this basis,the chemical co-precipitation method was adopted.YCl₃·6H_(2)O,CrCl₃·6H_(2)O,and MnCl₂·4H_(2)O were calculated,weighed,and batched according to a total mass of 100 g.They were dissolved in 5 mL of deionized water and continuously stirred.In a reverse addition manner,the solution was added to ammonia water and continuously stirred,keeping the pH of the solution at around 10.After stirring for 2 h,the solution was allowed to stand for precipitation.The supernatant was poured off,and the precipitate was washed with d

关 键 词：化学共沉淀法 热敏常数 固相法 热敏陶瓷 钙钛矿 

分 类 号：TB4[一般工业技术] TP212[自动化与计算机技术—检测技术与自动化装置]