The influence of iron substitution to manganese on the physical properties of YMnO3

Structural, electric and magnetic properties of YMn1-xFexO3 based ceramic compounds have been studied. The samples, prepared by a solid state reaction method, were characterized by X-ray diffraction (XRD), electric (R(T)) and magnetic measurements (M(T)). The XRD analysis has showed that the structure of these compounds change by the increase in degree of substitution from the hexagonal (P63cm Space Group (SG)) to the orthorhombic perovskite (Pbnm SG). Similarly, the electrical properties varied with the materials becoming less resistive with an increase in the iron content and the relation between the thermistor constant (B) and temperature became linearly dependent. The magnetic characterization showed that with an increase in the iron content, the Curie temperature of antiferro-paramagnetic transition shift to higher values. At the same time, the values of effective magnetic momentum (mueff) decrease as the iron content increases. The study highlights the possibility of modelling these materials for improved properties, intended to negative temperature coefficient (NTC) type thermistor applications.