Enhancing the temperature coefficient of resistance and magnetoresistance properties of La 0.7− x Eu x Ca 0.3 MnO 3 ceramics by Eu 3+ doping

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Abstract La 0.7 Ca 0.3 MnO 3 ceramics have garnered significant attention from researchers due to their intriguing magnetoelectric properties and their potential applications in components for infrared detection and magnetic sensing devices. However, the magnetoelectric transport mechanisms within the material require detailed examination, and its properties must be further refined to better support practical implementation. In this study, we synthesized Eu 3+ doped La 0.7− x Eu x Ca 0.3 MnO 3 (LECMO) using the sol–gel technique and analyzed its structure, surface morphology, resistivity, temperature coefficient of resistance (TCR), and magnetoresistance (MR) properties. According to the x‐ray diffractometer results, the lattice parameters and unit cell volume decrease with increasing Eu 3+ content. Scanning electron microscope analysis confirms the excellent sintering quality of the samples and a homogeneous distribution of elements. The electrical transport properties at low temperatures were studied using various competitive scattering mechanisms. The variable‐range hopping model and small polaron hopping model were employed to investigate the electrical transport mechanisms at high temperatures, whereas the phenomenological percolation model was used to analyze the transport characteristics in the transition region. Moreover, the TCR of LECMO ceramics was enhanced to 41.14% K −1 , and the MR value reached 92.73%. Such improvements offer LECMO ceramics greater prospects for practical applications.

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