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In this work we have reported the temperature and magnetic field dependence of resistivity and magnetoresistance in electron-doped polycrystalline Ca 0.85 Sm 0.15 MnO 3 (CSMO). It shows a robust semiconducting behavior down to the lowest temperature (5 K) of investigation. High- T resistivity of the present sample follows small polaron hopping (SPH) conduction mechanism. The variable range hopping (VRH) model has been found to fit low- T resistivity data. Intermediate-temperature ρ ( T ) data has been explained using a parallel combination of SPH and 3D-VRH model. The resistivity shows strong dependence on the magnetic field–temperature history. Magnetoresistance (MR) of the sample shows strong irreversibility with respect to sweeping of the field between the highest positive and negative values. Low- ρ state of the envelope curve in MR indicates a manifestation of kinetic arrest of the electronic phase on application of magnetic field. We demonstrates that the sizable MR at low fields dominated by spin-polarized tunneling between the adjacent grains. [ABSTRACT FROM AUTHOR]

• Single phase polycrystalline Fe 3 Si films were acquired on MgO/Si(1 1 1). • The distribution of scattered particles embedded in films results in rough surface. • The performance of Fe 3 Si films is improved with the increase of atomic ordering. • Anomalous SMS is a unique character of the ferromagnetic Heusler alloy films. • Berry curvature dominates the AHE via a proper scaling law. This work intended to give a comprehensive overview of the atomic ordering dependence of magnetic and magneto-transport properties for polycrystalline Fe 3 Si films on Si(1 1 1) substrates by inserting the MgO buffer layer between them. X-ray diffraction results display that the single phase polycrystalline Fe 3 Si film fulfilling fundamental reflections, B 2 -Fe 3 Si film and D0 3 -Fe 3 Si film are acquired. Scanning electron microscopy images present the distribution of the particles dispersed and embedded in the films, resulting in rough surface. The M s value increases and H c value decreases with the improvement of structural and chemical order. The highly ordered D0 3 -Fe 3 Si film has the highest M s value of 610~657 emu cm−3, and the lowest H c value of 81~93 Oe. Fe 3 Si films characterize metallic behavior and the resistivity declines with the improvement of atomic ordering. The phonon contribution governs the resistivity in the high temperature range and the electron–electron scattering and anomalous single magnon scattering mechanisms are available at the low temperature region of ~30 K~100 K and below ~30 K, respectively. The analysis of anomalous Hall effect demonstrates that Berry curvature dominates the anomalous Hall effect via a proper scaling law. The enhancement of intrinsic anomalous Hall effect contribution is due to the impact of the improvement of structural and chemical order on the band structure/Berry curvature modifications, accordingly affecting the intensity of spin–orbit coupling, whereas the extrinsic contributions behave in opposite manner. [ABSTRACT FROM AUTHOR]

• Pr 0.5 Ca 0.5 Mn 0.9 V 0.1 O 3 crystallizes in O′–type orthorhombic structure and Pnma space group. • The onset of CO at 233 K and spin-glass behavior observed at low temperature regime. • V doping incorporates a field-induced metal–insulator transition with low-temperature Kondo-type behavior. • Large irreversibility in both the M-H and ρ-H plots are observed at low temperature region. • Large values of MR ~ 99.99% and FCR ~ 855% of the sample reveal its important applications. Structural, magnetic and magneto-transport properties of polycrystalline Pr 0.5 Ca 0.5 Mn 0.9 V 0.1 O 3 have been studied. The incorporation of vanadium attributes to enhancement in the Mn3+/Mn4+ ratio as well as density of conducting e g carriers, which affects the magnetic and electrical behavior of the system. On cooling, a multi-phase separated "paramagnetic (PM) – charge-ordered antiferromagnetic (COAFM) – ferromagnetic (FM) – reentrant spin glass (RSG)" phases are observed with the characteristic charge ordering temperature T CO = 233 K and Neel temperature T N = 143 K. Field-induced first-order magnetic phase transition from a charge-ordered antiferromagnetic state to a ferromagnetic cluster glass state takes place at T C = 44 K. A 7 T magnetic field induces metal–insulator transition at T MI = 163 K. At low temperatures, strong memory-effect and colossal magnetoresistance (CMR) ~ 99.99% are observed in resistivity data. The sample shows a high field coefficient of resistance (FCR) value of about 855% in the low-temperature regime. [ABSTRACT FROM AUTHOR]

Abstract: The magnetotransport and magnetostatic properties of synthesized dilute magnetic semiconductors (DMS) In x Mn1− x Sb were studied. The samples with x=0.75–1.33at% Mn manifested the hysteresis at room temperature with the coercive force below 50Oe and the saturation field about 5kOe. Both the magnetoresistance and Hall effect were positive. With the Mn concentration decrease the magnetoresistance significantly increased. The co-doping of these DMS with Zn enhances the ferromagnetic properties according to the kinematic exchange theory. [Copyright &y& Elsevier]