Increased sensibility of mixed ferrite humidity sensors by subsequent heat treatment

Abstract

The study presents the effects of different calcination temperatures on the size and morphology of mixed Co‐Ni ferrites, and the respective changes in the magnetic and electrical properties, with emphasis on their applicability as humidity sensors. The data suggests that the heat treatment does not significantly change the magnetic properties, but significant variations on the morphology of the nanoparticles, correlated with large changes in the electrical properties of the nanoparticles in terms of electrical permittivity and resistivity with electrical field frequency and humidity, with a clear influence of the calcination temperature over the sensibility of the materials to humidity.

MOFs-Derived Porous NiFe2O4 Nano-Octahedrons with Hollow Interiors for an Excellent Toluene Gas Sensor

“…), which are materials that include two types of transition metals, have stood out due to their robust catalytic activity as exhibiting significant potential applications in various fields. In particular, a few of them such as ZnFe 2 O 4 [13,14], NiFe 2 O 4 [15,16,17,18,19,20,21,22], CoFe 2 O 4 [23], MnFe 2 O 4 [24], Ni 1-X Co X Fe 2 O 4 [25], and NiCuZn ferrites [26] have been reported to be greatly promising in the electrical properties of gas sensors and humidity sensors. More interesting, NiFe 2 O 4 with various microstructures have been prepared so far to effectively detect acetone [14,15,16,17], ammonia [18], NO 2 [19], n-propanol [20], and triethylamine [21].…”

Shape-controlled CoFe2O4 nanoparticles as an excellent material for humidity sensing

“…3 Similarly, Seki et al reported ferrites as humidity sensitive by gaining precise insight into the electrical and magnetic characteristics of the materials. 4 A mixed Ni-Co ferrite and the effect of applied calcination temperature on the humidity sensing properties were reported by Virlan et al 5 The humidity sensing of so ferrites like mixed Cu-Zn system has also been observed where formulation of highly sensitive ferrites by doping was discussed as an alternative to the conventional metal oxide-based humidity sensors. 6 Muthurani et al reported the humidity sensing properties of Cu-, Co-and mixed Cu-Co ferrites where CuFe 2 O 4 showed better results than others at room temperature.…”

Investigation of ZnFe2O4 spinel ferrite nanocrystalline screen‐printed thick films for application in humidity sensing

“…Complex oxides, such as spinel oxides and especially spinel ferrites (unit formula AB 2 O 4 ) are very promising materials for sensing different gases, even though they have been much more widely applied as magnetic materials. Spinel ferrites have shown sensitivity to a wide variety of gases, such as H 2 O (humidity), CO, ethanol, acetone, VOCs …”