LaCr0.7Fe0.3O3-NiMn2O4 supported NTC composite ceramics with a sandwich-like structure

A novel sandwich-like structure was first proposed to adjust the electrical properties of NTC thermistors. The LaCr0.7Fe0.3O3-NiMn2O4 supported composite ceramics with sandwich-like structure were initially fabricated via traditional solid-state reaction and uniaxial pressing methods, which allowed for the advantages of each component to be integrated into one material. X-Ray diffraction analysis indicates the ceramics mainly consisting of orthorhombic perovskite LaCr0.7Fe0.3O3 and cubic spinel NiMn2O4 phases. SEM images manifest that the three layers adhered well to each other and exhibited high density. For electrical properties, the ?25?C was expanded to a wide range of 1182?110,233 ??cm and could be adjusted to the desired values by tuning the volume ratio of two basic layers, the B value was enhanced from 3358 K to 4167 K by NiMn2O4, and the thermal stability was improved by LaCr0.7Fe0.3O3 with a resistance shift less than 0.55 % after annealing at 150 ?C for 1500 h.

Automated summary

The novel sandwich-like structure proposed here for NTC thermistors demonstrates successful integration of LaCr0.7Fe0.3O3-NiMn2O4 supported composite ceramics with distinct electrical properties. X-ray diffraction analysis reveals the composition mainly consisting of orthorhombic perovskite LaCr0.7Fe0.3O3 and cubic spinel NiMn2O4 phases. The three layers exhibit good adhesion and high density, allowing for adjustment of electrical properties and improved thermal stability.