Magnetic and Magneto-Transport Measurements of 57Fe-doped SrCoO3 and Sr1-x Cd x CoO3 Perovskites

In this article, the magneto-transport features of Fe-57 isotope (1%) doped SrCoO3 (referred to as SrCo0.99 (Fe0.01O3)-Fe-57) perovskite compound have been investigated. The compound crystallized in cubic symmetry undergoes ferromagnetic transition around similar to 270 K. The isothermal magnetization data collected at low temperature (1.8 K) indicates a characteristic of soft ferromagnet with saturation moment, M (s similar to)1.81 mu (B)/Co. Interestingly, the electrical resistivity, rho(T), measurements indicate semiconducting properties while metallic nature is seen for the pristine compound. The SrCo0.99 (Fe0.01O3)-Fe-57 sample shows temperature and field dependence of magnetoresistance, MR, around 1.5%, which is rather smaller than of the pristine perovskite. The second part of the present work reports the attempt to dope Cd on Sr-site in the perovskite structure, Sr1-x Cd (x) CoO3, under extreme conditions. A minimum amount of about x=0.05, 0.1 is tested for solid solution in the Sr1-x Cd (x) CoO3 structure. However, the structural data indicate that Cd is not fully doped in the matrix for x=0.05, 0.1 samples; some of the CdO is intact as an impurity and it did not show major impact on the physical properties of the samples. The rho(T) data reveal metallic nature for both x=0.05 and 0.1 samples with relatively low resistivity at low temperature regions, and they exhibit -MR similar to 4% around similar to 250 K. For x=0.05 the molar magnetic susceptibility of the sample shows ferromagnetic transition at T (c)=244 K, whereas x=0.1 sample exhibits ferromagnetism at T (c)=264 K. The effective Bohr magnetron parameter, p (eff), determined for x=0.05 and 0.1 samples is found to be 3.10 mu (B)/Co and 3.25 mu (B)/Co, respectively, and these data suggest intermediate spin state for Co4+ ion for both the samples. The M(H) data for both the samples reveal soft ferromagnetism. The M (s) of x=0.05 reaches 1.9 mu (B)/Co and of x=0.1 reaches 1.86 mu (B)/Co at 1.8 K and 70 kOe conditions.