The magnetic exchange between epitaxial thin films of the multiferroic (antiferromagnetic and ferroelectric) hexagonal YMnO3 oxide a soft ferromagnetic (FM) layer is used to couple response FM state antiferromagnetic one. We will show that biasing ferroelectric by an electric field allows control bias subsequently magnetotransport properties layer. This finding may contribute paving way towards new generation electric-field controlled spintronic devices.

The magnetic properties of ferromagnetic-antiferromagnetic Co-CoO core-shell nanoparticles are investigated as a function the in-plane coverage density from 3.5% to 15%. superparamagnetic blocking temperature, coercivity, and bias field radically increase with increasing coverage. This behavior cannot be attributed overall interactions between cores. Rather, it can semiquantitatively understood by assuming that shells isolated have strongly degraded properties, which rapidly recovered come...

The crystal and magnetic structures of orthorhombic ε-Fe2O3 have been studied by simultaneous Rietveld refinement X-ray neutron powder-diffraction data in combination with Mössbauer spectroscopy, as well magnetization heat-capacity measurements. It has found that above 150 K, the polymorph is a collinear ferrimagnet moments directed along axis, whereas ordering below 80 K characterized square-wave incommensurate structure. transformation between these two states second-order phase transition...

The Fe3+ lattice in the Bi2Fe4O9 compound is found to materialize first analogue of a magnetic pentagonal lattice. Due its odd number bonds per elemental brick, this lattice, subject neighbor antiferromagnetic interactions, prone geometric frustration. properties have been investigated by macroscopic measurements and neutron diffraction. observed non-collinear arrangement related one stabilized on perfect tiling as obtained from mean field analysis with direct space configurations...

We demonstrate that the magnetization of a ferromagnet in contact with an antiferromagnetic multiferroic (LuMnO(3)) can be speedily reversed by electric-field pulsing, and sign magnetic exchange bias switch recover isothermally. As LuMnO(3) is not ferroelastic, our data conclusively show this switching mediated strain effects but unique driven decoupling ferroelectric domain walls. Their distinct dynamics are essential for observed switching.

Proper estimation of magnetization curve parameters is vital in studying magnetic systems. In the present article, criteria for discrimination non-saturated (minor) from saturated (major) hysteresis loops are proposed. These employ analysis (i) derivatives both ascending and descending branches loop, (ii) remanent curves, (iii) thermomagnetic curves. Computational simulations used order to demonstrate their validity. Examples illustrating applicability these well-known real systems, namely...

The phonon structure of antiferromagnetic ${\text{Bi}}_{2}{\text{Fe}}_{4}{\text{O}}_{9}$ (space group $Pbnm$ No. 55, ${T}_{N}\ensuremath{\approx}240\text{ }\text{K}$) was studied theoretically by calculations lattice dynamics and experimentally between 10 300 K polarized Raman spectroscopy. Most the $12{A}_{g}+12{B}_{1g}+9{B}_{2g}+9{B}_{3g}$ modes were unambiguously identified. Strong second-order scattering observed for $ab$-plane-confined incident scattered light polarizations. In addition...

Thermal activation tends to destroy the magnetic stability of small nanoparticles, with crucial implications for ultrahigh density recording among other applications. Here we demonstrate that low-blocking-temperature ferromagnetic (FM) Co nanoparticles (T(B)<70 K) become magnetically stable above 400 K when embedded in a high-Néel-temperature antiferromagnetic (AFM) NiO matrix. The origin this remarkable T(B) enhancement is due proximity effect between thin CoO shell (with low Néel...

Apart from being so far the only known binary multiferroic compound, CuO has a much higher transition temperature into state, 230 K, than any other material in which electric polarization is induced by spontaneous magnetic order, typically lower 100 K. Although magnetically ferroelectricity of firmly established, no magnetoelectric effect been observed as direct crosstalk between bulk magnetization and counterparts. Here we demonstrate that high fields about 50 T are able to suppress helical...

A route toward enhancing the energy product $(\mathrm{BH}{)}_{\mathrm{max}}$ of permanent magnetic materials, at room temperature, based on ferromagnetic-(FM-) antiferromagnetic (AFM) exchange interactions has been developed. The coupling, which is induced by ball milling hard ${\mathrm{SmCo}}_{5}$ with AFM NiO powders, results in an enhancement coercivity ${H}_{C}$ and squareness ratio ${M}_{R}{/M}_{S}$ (remnant-saturation magnetizations), depends FM:AFM processing conditions. However,...

Nanocomposite FePt/C and FePt/BN thin films have been fabricated by dc rf magnetron sputtering on naturally-oxidized Si[100] substrates. Particles consisting of the highly anisotropic tetragonal L1/sub 0/ FePt phase were obtained annealing as-made multilayers a conventional vacuum furnace in temperature range 500 to 800/spl deg/C. By controlling conditions, samples with grain size 3 20 nm obtained, coercivities between 2 16 kOe. The evolution crystal structure during at 600/spl deg/C was...

Thin films of the metastable and elusive ε-Fe2O3 have been epitaxially stabilized on SrTiO3 (111) substrates. The present a (001) orientation perpendicular to substrate three in-plane domains measuring few nanometers showing atomically sharp interfaces. We argue that this domain structure, rather than epitaxial-strain, plays an essential role in stabilizing by minimizing energy (100) surfaces. show large coercivity ∼8 kOe which combined with magnetoelectric character claimed for oxide may...

We have studied the magnetic anisotropy of nanometric CoFe2O4 (CFO) thin films grown on (100)SrTiO3 (STO) substrates. It has been found that epitaxial substrate-induced compressive strain makes normal-to-film axis harder than in-plane directions. In agreement with some previous reports, magnetization loops are to display a characteristic shrinking at low fields. Detailed structural and microstructural analyses, together modeling loops, revealed microstructure films, namely, coexistence...

Manganites of the series , with x = 0, 0.1, 0.3, 0.5, 0.7 and 1.0, have been characterized in ceramic form thin films prepared by pulsed laser deposition. Characterization techniques included x-ray diffraction, conductivity magnetoresistance, magnetization susceptibility, optical spectroscopy Faraday effect. Both ceramics exhibit a maximum low-temperature at which is coexistent ferromagnetic order. The negative magnetoresistance effect qualitatively different for 0.3 0.5 compositions. For...

We show that in oxide thin films of spiral antiferromagnetic orthorhombic TbMnO3, ferromagnetism emerges resulting from epitaxially induced strain. The unit cell volume can be tuned (contracting up to a 2%) by varying thickness and deposition conditions; it is found the ferromagnetic response correlates with deformation. Such effect strain on magnetic properties turns out similar occurring collinear antiferromagnets such as YMnO3. Owing intimate relationship between order ferroelectricity...

The susceptibility of ${(\mathrm{S}\mathrm{m}}_{0.65}{\mathrm{Sr}}_{0.35}{)\mathrm{M}\mathrm{n}\mathrm{O}}_{3}$ shows an unusual temperature dependence above the Curie which is attributed to presence small manganese-ion clusters with $S\ensuremath{\approx}9.$ A field-induced transition observed in paramagnetic state, corresponds a doubling cluster size and increase strength interaction between them. continuous from large interpreted terms electron phase segregation two-phase region. Magnetic...

The magnetic structures of the incommensurate phases prototypic multiferroic MnWO${}_{4}$ are analyzed using superspace symmetry formalism. This approach shows in a very simple way relation between and any tensorial property, such as ferroelectricity. have been redetermined by single-crystal neutron diffraction experiments, which revealed fine details AF3 AF2 structures. spin modulations two manganese ions basic unit cell symmetry-related paraelectric incommensurate-magnetic structure...

Self-assembled (0.65)BiFeO3–(0.35)CoFe2O4 (BFO-CFO) nanostructures were deposited on SrTiO3 (001) and (111) substrates by pulsed laser deposition at various temperatures from 500to800°C. The crystal phases the lattice strain for two different substrate orientations have been determined compared. films grow epitaxial both but separation of spinel perovskite crystallites, without parasitic phases, is only obtained growth around 600–650°C. BFO crystallites are out-of-plane expanded STO(001),...

Interface physics in oxides heterostructures is pivotal material's science. Domain walls (DWs) ferroic systems are examples of naturally occurring interfaces, where order parameter neighboring domains modified and emerging properties may develop. Here we show that electric tuning ferroelastic domain SrTiO3 leads to dramatic changes the magnetic structure a layer (La1/2Sr1/2MnO3) epitaxially clamped on substrate. We intimately connected existence polar regions at twin boundaries SrTiO3,...