A dual-function negative temperature coefficient thermistor (NTCR/AB) has been successfully fabricated from the available and inexpensive Egyptian raw materials (clay and nepheline tailings). The disc-shaped thermistor was fabricated by grinding and mixing its raw material in a porcelain ball mill for 1 h, drying at 110°C for 1 h, pressing under 30 kN, drying at 110°C for 24 h, firing at 550°C, and finally sintering at 1200°C for 1 h. The crystalline phases developed in the ceramic thermistor were characterized by x-ray diffraction. The thermistor performance has been examined by measuring its electrical resistivity (ρ) over a wide range of temperature (− 100°C to + 200°C) at a constant frequency (0.1 Hz), using a broadband dielectric spectrometer. The fabricated ceramic thermistor showed a decrease in resistivity with increasing temperature at two different rates, displaying the NTCR/AB. One of its functions (NTCR/B) works in a wide temperature range (− 20°C to 200°C) and shows high thermistor constant values (3009–4638 K), while its second function (NTCR/A) works in a narrower temperature range (− 40°C to − 20°C) and shows exceptionally high thermistor constant values (40,122 K). NTCR/B can be used for many electronic devices applications, while NTCR/A is promising for thermal switching devices.

双功能负温度系数热敏电阻（NTCR / AB）已成功地从可用的廉价埃及原材料（粘土和霞石尾矿）中制造出来。圆盘形热敏电阻是通过将其原料在瓷球磨机中研磨并混合1 h，在110°C干燥1 h，在30 kN下加压，在110°C干燥24 h，在550°C焙烧而制成的C，最后在1200°C烧结1小时。陶瓷热敏电阻中形成的结晶相通过X射线衍射表征。通过测量热敏电阻的电阻率（ρ）使用宽带介电谱仪以恒定频率（0.1 Hz）在较宽的温度范围（− 100°C至+ 200°C）下进行测量）。制成的陶瓷热敏电阻在两种不同的速率下均随温度升高而降低了电阻率，从而显示出NTCR / AB。其功能之一（NTCR / B）在较宽的温度范围（− 20°C至200°C）下工作，并显示出较高的热敏电阻常数值（3009–4638 K），而其第二功能（NTCR / A）在以下温度范围内工作：更窄的温度范围（− 40°C至− 20°C），并且显示出异常高的热敏电阻常数值（40,122 K）。NTCR / B可用于许多电子设备应用，而NTCR / A有望用于热开关设备。