WANG ^Dian， XIE ^Guangyuan， LV ^Juntao， LI ^Wanwan

School of Materials and Metallurgy， Wuhan University of Science and Technology， Wuhan 430081， China

Abstract

Objective Negative temperature coefficient （NTC） thermistors are widely used in fields such as automotive electronics， household appliances， aerospace， and medical equipment due to their ability to measure temperature， provide temperature compensation， 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 yYCrxMn_1-xO₃-（1-y）Y₂O₃ system by adjusting the x and y ratios.

Methods Initially， eight different x and y ratios of rare earth perovskite NTCs were prepared using the solid-phase method. X-ray diffraction （XRD） and electrical performance analysis were used to select the optimal set （x=0.3， y=0.6）. Based on this， four groups of powders with smaller particle sizes and higher uniformity were prepared for the yYCr_0.3Mn_0.7O₃-（1-y）Y₂O₃ system using the chemical co-precipitation method. NTC ceramics were obtained through calcination and pressing， and the effects of the co-precipitation method on the performance of the products were examined.

Results and Discussion In the yYCr_0.3Mn_0.7O₃-（1-y）Y₂O₃ system prepared by the co-precipitation method， when y≥0.6， the thermal sensitivity constant B25/85 was ≥2180 K， and the activation energy Ea was ≥0.19 eV. Conclusion By increasing the mass fraction of Mn⁴⁺ and decreasing the mass fraction of Y₂O₃， the yYCr_0.3Mn_0.7O₃-（1-y）Y₂O₃ phase content can be increased， thereby reducing the material’s resistivity. This leads to improved sensitivity of the resistive value to temperature changes， reflected by an increase in the thermal sensitivity constant （B value）.

Keywords： chemical co-precipitation method； thermal constant； solid-phase method； thermistor ceramics； perovskite

Get Citation:WANG Dian， XIE Guangyuan， LV Juntao， et al. Effect of co-precipitation method on characteristic values of yYCr_xMn_1-xO₃-（1-y） Y₂O₃ system［J］. China Powder Science and Technology， 2025， 31（2）： 1-7.

Received:2023-12-07.Revised:2024-05-13,Online:2025-02-25.

Funding Project:国家自然科学基金项目，编号：51904213。

First Author:王典（1999—），女，硕士生，研究方向为热敏陶瓷传感器的工艺设计。E-mail：2876136728@qq. com。

Corresponding Author:谢光远（1965—），男，教授，博士，硕士生导师，研究方向为传感器的开发。E-mail：121521197@qq. com。

DOI：10.13732/j.issn.1008-5548.2025.02.009

CLC No: TB4；TP212              Type Code:A

Serial No:1008-5548（2025）02-0001-07