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The performance of the spintronic devices is highly dependent on spin polarization. Here, we have performed the first-principles DFT calculation for L21-ordered and B2-disordered Co2FeSi Heusler alloys along with the effect of lattice strain on spin polarization. In both cases, the spin polarization decreases, but the total magnetic moment increases. For experimental study, Co2FeSi/SiO2/p-Si heterostructures have been fabricated by growing codeposited Co2FeSi film on p-type silicon. Experimentally, we demonstrate the accumulation of spin-polarized carriers in p–Si from B2-ordered half-metal Co2FeSi film by measuring magnetic field-dependent electrical transport properties of the device using self-formed SiO2 as a tunnel barrier. Magnetic field-dependent current (I)–voltage (V) behavior of the device shows a prominent spin-valve effect at low temperature. Spin polarization of the device has been calculated by measuring the current across the heterostructure in the presence of a magnetic field.

We present the synthesis and a detail investigation of structural and magnetic properties of polycrystalline [VO(HCOO)2·(H2O)] by means of x-ray diffraction, magnetic susceptibility, highfield magnetization, heat capacity, and electron spin resonance measurements. It crystallizes in a orthorhombic structure with space group P cca. It features distorted VO6 octahedra connected via HCOO linker (formate anions) forming a two-dimensional square lattice network with a bilayered structure. Analysis of magnetic susceptibility, high field magnetization, and heat capacity data in terms of the frustrated square lattice model unambiguously establish quasi-two-dimensional nature of the compound with nearest neighbour interaction J1/kB 11.7 K and next-nearest-neighbour interaction J2/kB 0.02 K. It undergoes a Néel antiferromagnetic ordering at TN 1.1 K. The ratio θCW/TN 10.9 reflects excellent two-dimensionality of the spin-lattice in the compound. A strong in-plane anisotropy is inferred from the linear increase of TN with magnetic field, consistent with the structural data.

In this article, we have studied the changes in structural, magnetic, and magneto-transport properties of Bi2Te3 topological insulator doped with magnetic (Fe) as well as non-magnetic (In) elements. The un-doped along with Fe, In-doped Bi2Te3 are grown using a melt growth technique. The Rietveld analysis of x-ray diffraction data expresses that both In and Fe-dopants substituted the Bi-position with a little bit of interstitial incorporation in host Bi2Te3. It is also noticed that In-doping is slightly favorable for Bi-substitution than Fe. The magnetic characterization reveals a mixing of diamagnetic and Pauli paramagnetic behavior of un-doped and In-doped Bi2Te3, whereas, Fe-doping shows overall paramagnetism with local anti-ferromagnetic interactions among Fe-ions without long-range order. Electrical-transport study represents the metallic response of host Bi2Te3, which is well-maintained for In-doping; however, Fe-doping exhibits prominent anomalies in ρ_xx –T profiles. Importantly, magneto-conductance research indicates a notable deviation of host quantum feature, weak anti-localization effect (WAL) upon magnetic (Fe) doping, whereas non-magnetic In-doping shows a comparatively weak deviation in WAL effect for high doping limit.

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The polycrystalline CoFe2O4 (CFO) film on cantilever substrate of silicon was grown using pulsed laser deposition (PLD) method and investigated its in-plane and out-of-plane magnetostrictive strain at room temperature (300 K) using the indigenous optical Cantilever Beam Magnetometer (CBM). The film shows a high compressive magnetostrictive strain of ‒ 387 ppm and ‒ 708 ppm for in-plane and out-of-plane configurations, respectively. Considerably, the magnetostrictive strain loops (λ‒H) possess a certain degree of hysteresis with a symmetric butterfly shape. The origin of large compressive magnetostriction of CFO film is attributed to the non-180° domain wall motion followed by 90° domain rotation. The large values of saturation magnetostrictive strain make CFO film a suitable candidate in sensor design for different purposes.

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