ACTA

Structural, Magnetic and Magnetotransport Properties of La_0.7Ca_0.18Ba_0.12Mn_0.95Sn_0.05O₃ Perovskite Manganite

I. Belal^a, F. Meriche^a, N. Mahamdioua^b, J.A. Alonso^c, J.L. Martinez^c, S. Polat-Altintas^d, C. Terzioglu^d
^aLEM laboratory, Department of Physics, University of Jijel, Jijel 18000, Algeria
^bLEND Laboratory, Faculty of Science and Technology, University of Jijel, Jijel 18000, Algeria
^cInstituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain
^dDepartment of Physics, Faculty of Arts and Sciences, AIB University, Bolu 14280, Turkey

Full Text PDF

This paper reports a study on the structural, magnetic and magnetotransport properties of the mixed-valence perovskite manganite La_0.7Ca_0.18Ba_0.12Mn_0.95Sn_0.05O₃ (LCBMSO), synthesized by a solid-state reaction method. The results of X-ray powder diffraction analysis confirm that the sample possesses a single orthorhombic phase with space group Pnma. The Rietveld refinement results reveals that LCBMSO contains distorted MnO₆ octahedron. Micrographs obtained by scanning electron microscopy showed that the sample grains have a polygonal shape and are in the micrometer size range. Fourier transform infrared spectroscopy analysis confirms the presence of Mn-O-Mn and Mn-O stretching vibration. The magnetization-temperature curve displays a paramagnetic-ferromagnetic transition at T_C=145 K. A slight bifurcation between the zero-field curve and the cooling-field curve was noticed, which is attributed to spin-glass behavior. Based on the hysteresis cycle, a soft ferromagnetic behavior was observed in our sample at temperatures of 1.8 and 100 K. The electrical resistivity vs temperature curve shows a metal-insulator transition at T_MI=154 K. The magnetoresistance ratio reached 30% at an applied magnetic field of 1 T, making the LCBMSO material an attractive candidate for use as a magnetoresistive sensor in various industrial applications. The temperature coefficient of resistivity reached 3.35%, making this material suitable for use in infrared and bolometric detectors. The relation ρ=ρ₀-ρ_0.5T^0.5+ρ₂T²+ρ₅T⁵ was employed to fit the low-temperature resistivity data below T_MI, whereas the variable range hopping and small polaron hopping models were used to fit the data in the insulating region above T_MI.

DOI:10.12693/APhysPolA.149.65
topics: manganites, magnetic properties, magnetotransport properties, temperature coefficient of resistivity