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Abstract Linear magnetoresistance (LMR) is a special case of a magnetic-field induced resistivity response, which has been reported in highly disordered semiconductor systems and in topological materials. In this work, we observe LMR effect in half-metallic perovskite Sr2CrMoO6 thin films, of which the maximum MR value exceeds +1600% at 2 K and 14 T. It is an unusual behavior in ferrimagnetic double perovskite material like Sr2CrMoO6, which are known for intrinsic tunneling-type negative magnetoresistance. In the thin films, the high carriers’ density (~1022 cm−3) and ultrahigh mobility (~104 cm2 V−1 s−1) provide a low-resistivity (~10 nΩ·cm) platform for spin-polarized current. Our DFT calculations and magnetic measurements further support the half-metal band structure. The LMR effect in Sr2CrMoO6 could possibly originate from transport behavior that is governed by the guiding center motion of cyclotron orbitals, where the magnetic domain structure possibly provides disordered potential. The ultrahigh mobility and LMR in this system could broaden the applications of perovskites, and introduce more research on metallic oxide ferri-/ferro-magnetic materials.

We prepared 300-nm GeTe thin films on (111)-oriented and piezoelectrically active 0.71 Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-0.29 PT) single-crystal substrates by the pulsed laser deposition and investigated the effects of in situ electric-field-controllable non-180° ferroelastic domain switching of the PMN-0.29 PT on the electronic properties of the GeTe films. The in-plane strain of the PMN-0.29 PT could be modulated continuously and reversibly by electric fields in a nonvolatile manner and could be effectively transferred to the GeTe films. Based on this, we realized reversible and nonvolatile resistance switching and obtained multilevel stable nonvolatile resistance states with good stability and endurance at T = 300 K by applying appropriate asymmetrical bipolar electric fields to the PMN-0.29 PT(111) substrates along the thickness direction. Such heterostructures may be used for multilevel data storage that allows each unit to store multiple bits of information and thus improve the memory density. Our investigation would be beneficial for the fabrication of nonvolatile memory devices using PMN-xPT-based heterostructures. Keywords: Ferroelastic strain, Electronic transport, PMN-PT, Heterostructure, Strain effect

We report the fabrication of lead-free multiferroic structures by depositing ferromagnetic La0.7 Sr0.3 (LSMO) polycrystalline films on polished 0.5BaZr0.2Ti 0.8O3-0.5Ba 0.7Ca0.3TiO3 (BZT-BCT) piezoelectric ceramic substrates. By applying electric fields to the BZT-BCT along the thickness direction, the resistivity of LSMO films can be effectively manipulated via the piezoelectric strain of the BZT-BCT. Moreover, the LSMO polycrystalline films exhibit almost temperature independent and significantly enhanced magnetoresistance (MR) below TC. At T = 2K and H = 8T, the MR of polycrystalline films is approximately two orders of magnitude higher than that of LSMO epitaxial films grown on (LaAlO3)0.3(SrAl1/2Ta1/2O3)0.7 single-crystal substrates. The enhanced MR mainly results from the spin-polarized tunneling of charge carriers across grain boundaries. The LSMO/BZT-BCT structures with electric-field controllable modulation of resistivity and enhanced MR effect may have potential applications in low-energy consumption and environmentally friendly electronic devices. [ABSTRACT FROM AUTHOR]