Akademik Veri Yönetim Sistemi
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, cilt.32, sa.11, ss.14301-14309, 2021 (SCI-Expanded)
In the present research, the Pr0.67Ba0.22Sr0.11Mn1-xNixO3 (x = 0.025 and x = 0.05) manganite oxides were prepared using the solid-state reaction. X-ray diffraction (XRD), impedance spectroscopy technique and magnetization measurements are used to investigate the structural, electric, magnetic and magnetocaloric properties. Rietveld refinement of the XRD pattern indicates that the samples crystallize in the orthorhombic structure with Pnma space group. For the compounds, conductivity analysis confirmed that the existence of two metal-semiconductor transitions in the temperature range. The total conductance spectrum at different electric fields of the Pr0.67Ba0.22Sr0.11Mn0.95Ni0.05O3 sample is well defined by the Jonscher power law:G(w) = G(dc) + A omega(n1) + A omega(n2). Magnetic measurements reveal a ferromagnetic (FM) to paramagnetic (PM) transition with increasing temperature. The transition temperature was obtained from temperature-dependent magnetization measurements. The results shows that with increasing Ni content, it increases from T-C= 226 K for x = 0.025 to T-C = 255 K for x = 0.05. In order to determine the magnetic entropy change values of the samples, isothermal magnetization measurements, M(H), up to 5T applied magnetic field were carried out in their corresponding transition temperature regions. The maximum magnetic entropy change values were calculated from M(H) measurements as 2.30 and 2.95 Jkg(-1) K-1 for x = 0.025 and x = 0.05, respectively.