| 1. |
- Huang, Ke, et al.
(författare)
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Tailoring magnetic order via atomically stacking 3d/5d electrons to achieve high-performance spintronic devices
- 2020
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Ingår i: Applied Physics Reviews. - : AMER INST PHYSICS. - 1931-9401. ; 7:1
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Forskningsöversikt (refereegranskat)abstract
- The ability to tune magnetic orders, such as magnetic anisotropy and topological spin texture, is desired to achieve high-performance spintronic devices. A recent strategy has been to employ interfacial engineering techniques, such as the introduction of spin-correlated interfacial coupling, to tailor magnetic orders and achieve novel magnetic properties. We chose a unique polar-nonpolar LaMnO3/SrIrO3 superlattice because Mn (3d)/Ir (5d) oxides exhibit rich magnetic behaviors and strong spin-orbit coupling through the entanglement of their 3d and 5d electrons. Through magnetization and magnetotransport measurements, we found that the magnetic order is interface-dominated as the superlattice period is decreased. We were able to then effectively modify the magnetization, tilt of the ferromagnetic easy axis, and symmetry transition of the anisotropic magnetoresistance of the LaMnO3/SrIrO3 superlattice by introducing additional Mn (3d) and Ir (5d) interfaces. Further investigations using in-depth first-principles calculations and numerical simulations revealed that these magnetic behaviors could be understood by the 3d/5d electron correlation and Rashba spin-orbit coupling. The results reported here demonstrate a new route to synchronously engineer magnetic properties through the atomic stacking of different electrons, which would contribute to future applications in high-capacity storage devices and advanced computing.
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| 2. |
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| 3. |
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| 4. |
- Jiang, Qing-Hui, et al.
(författare)
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Ferroic properties of highly dense multiferroic Bi1-xLa0.05TbxFeO3 ceramics via sheltered spark plasma sintering
- 2008
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Ingår i: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 91:7, s. 2189-2194
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Tidskriftsartikel (refereegranskat)abstract
- Multiferroic Bi0.95-xLa0.05TbxFeO3 (BLTFO) ceramics were prepared by spark plasma sintering. The protection of CeO2 powders in the spark plasma sintering process can effectively restrain the valence fluctuation of iron ions and high-dense BLTFO ceramics with good dielectric and ferroelectric properties are fabricated. The BLTFO ceramics have low loss (tan delta similar to 5%) between 10(2) and 10(6) Hz. The doping of Tb can increase the dielectric and ferromagnetic properties, but decrease the ferroelectricity of BLTFO ceramics.
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| 5. |
- Jiang, Q. H., et al.
(författare)
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High-temperature ferroelectric phase transition observed in multiferroic Bi0.91La0.05Tb0.04FeO3
- 2009
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 95:1, s. 12909-
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Tidskriftsartikel (refereegranskat)abstract
- A single-phase Bi0.91La0.05Tb0.04FeO3 polycrystalline ceramic was fabricated by spark-plasma-sintering the precursor powder prepared by a sol-gel method. Temperature-dependent properties of polycrystalline Bi0.91La0.05Tb0.04FeO3 were characterized by x-ray diffraction, dielectric, and piezoelectric measurement. The x-ray diffraction results revealed a phase transition near 700 degrees C. Especially, temperature-dependent dielectric behavior demonstrated that there was a dielectric abnormal peak at about 697 degrees C, in addition to those two well-known dielectric abnormal peaks at 337 degrees C (Neel temperature) and 831 degrees C (Curie temperature). The observations, together with thermal depoled behavior, suggest a ferroelectric-ferroelectric phase transition from R(3)c to Pbnm at around 700 degrees C.
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| 6. |
- Jiang, Q. H., et al.
(författare)
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Magnetoelectric composites of nickel ferrite and lead zirconnate titanate prepared by spark plasma sintering
- 2007
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Ingår i: Journal of the European Ceramic Society. - : Elsevier BV. - 0955-2219 .- 1873-619X. ; 27:1, s. 279-284
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Tidskriftsartikel (refereegranskat)abstract
- Magnetoelectric (ME) bulk composites of ferrite and lead zirconnate titanate (PZT) were prepared by spark plasma sintering (SPS) of mechanically mixed ferrites. BaFe2O4 or NiFe2O4 and a soft lead zirconnate titanate, PZT-5A, powders. The feasibility of retarding possible reactions occurring between the ferrite and lead zirconnate titanate was approved by applying such a dynamic process as SPS. It was further revealed that nickel ferrite and PZT-5A is a more favorable combination that underwent no obvious reactions up to 1050 degrees C. Efforts were made to optimize the SPS processing parameters in order to produce immiscible composites with high electrical resistivity, low dielectric loss and better magnetoelectric response.
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| 7. |
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| 8. |
- Lin, Yuan-Hua, et al.
(författare)
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Electrical transport properties of La2CuO4 ceramics processed by the spark plasma sintering
- 2007
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Ingår i: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 90:12, s. 4005-4008
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Tidskriftsartikel (refereegranskat)abstract
- Highly dense La2CuO4 ceramics have been prepared by the spark plasma sintering technique. Temperature dependence of electrical conductivity indicates that La2CuO4 ceramics sintered at over 875 degrees C exhibit a metal-like behavior, which should be ascribed to the special La2CuO4 crystal structure and its correlation splitting of the half-filled d(x2-y2) band. Our experimental data indicate that all of the La2CuO4 samples exhibit positive thermoelectric power in the whole measuring temperature range, indicating that the majority of charge carriers are holes. It is desirable to obtain good thermoelectric performance for this system by optimizing the electrical properties and reducing the thermal conductivity.
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| 9. |
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| 10. |
- Shen, Zhijian, et al.
(författare)
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Ferroelectric ceramics with enhanced remnant polarization by ordered coalescence of nano-crystals
- 2012
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Ingår i: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 0959-9428 .- 1364-5501. ; 22:44, s. 23547-23552
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Tidskriftsartikel (refereegranskat)abstract
- An exceptional high ferroelectric remnant polarization (P-r) was observed in BaTiO3 ceramics owing to the formation of micron-sized grains possessing nano-scale mosaicity. Such a structural hierarchy was developed via a novel crystal-growth mechanism, namely ordered coalescence of nano-crystals achieved by synergetic atomic epitaxial growth and self-assembly of nano-crystals. The accommodating lattice defects in sub-grain boundaries due to the imperfect assembly of nano-crystals significantly contribute to the P-r enhancement by stimulating the dynamics of ferroelectric domain formation and switching. This finding defines a new approach to nanopowder sintering leading to enhanced properties sensitive to lattice defects.
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