High Quality Single Phase Research Articles

Combined 3d-4f magnetic interactions to manipulate long-range ferromagnetism in monoclinic double perovskites Gd-substituted [formula omitted][formula omitted]

Oxide double perovskites (DPs) with half-filled 4f Rare-earth (RE) elements along with partially-filled 3d transition-metals (TM) are rich source of exotic spin-orbital properties. Herein, we have investigated explicitly, the structural properties, spin-orbital ground states of the bulk phases and electronic structure of the RE-double perovskites Sm2−xGdxCoMnO6x=0.0,0.5,1.0,1.5 by synthesizing high quality single-phase samples and undertaking high precision experimental measurements of the transport and magnetic properties down to 8 K. In fact, we are able to show that with Gd-substitution, it lowers the value of the magnetoresistance in Sm2CoMnO6 (SCMO) and it is consistent with the observed Curie-Weiss temperature (TCW) which is lower than the observed ordering temperature (TC) upon Gd-substitution of Sm3+. Native presence of magnetic impurities (Co3+ and Mn3+) with low-spin S = 0 configurations in the SCMO vs. the nominal higher spin-state (Co2+ and Mn4+) with S = 3/2 is predicted. It essentially tunes super-exchange mechanism and relative ground states as compared to Gd2CoMnO6 (GCMO). The synergy of crystal structure and electronic structure to the magnetic properties are thus, established with first-principles calculations data, employing self-consistent Hubbard U (Uself) determination for both 3d- and 4f-site’s electronic correlation. The computed quenched spin-moments (∼20–40 %) in the experimental observation at the Sm3+(4f5) and Gd3+(4f7) sites from the ideal value 10.0 μB and 14.0 μB per f.u. is established, respectively. It could be due to magnetic impurities in their ferri-magnetic ground state ordering (FiM3), as also confirmed from present first-principles calculations in the pristine limit. In SCMO x=0.0, the valence band is dominated with the RE(4 f)-orbitals along with the TM(3d)- and O(2p)-orbitals, resulting it as a charge-transfer type semiconductor, while in GCMO x=1.5, Gd(4 f)-orbitals are localized well below 6.5 eV from Fermi level, EF = 0 eV, resulting it as a Mott-insulator-like, mediated via 3d-3d transitions. The long-range ferro-magnetic spin-ordering ground states in SCMO is established through non-collinear spin-orbital ground states determinations. Indeed, the long-range insulating FM ordering in SCMO from combined 3d-4f-sub-lattice’s magnetic interactions, but found to be broken with Gd-substitution (x = 0.5–1.5) aligning all 3d-4f site’s spins into the in-plane. Observed coercive field (HC) and remanence asymmetry (Mr), the nature of exchange-bias transformed from inverse to conventional type, as soon as it contains a small fraction of the Gd-substitution (x = 0.5).

Synthesis of metallic high-entropy alloy nanoparticles.

The theoretically infinite compositional space of high-entropy alloys (HEAs) and their novel properties and applications have attracted significant attention from a broader research community. The successful synthesis of high-quality single-phase HEA nanoparticles represents a crucial step in fully unlocking the potential of this new class of materials to drive innovations. This review analyzes the various methods reported in the literature to identify their commonalities and dissimilarities, which allows categorizing these methods into five general strategies. Physical minimization of HEA metals into HEA nanoparticles through cryo-milling represents the typical top-down strategy. The counter bottom-up strategy requires the simultaneous generation and precipitation of metal atoms of different elements on growing nanoparticles. Depending on the metal atom generation process, there are four synthesis strategies: vaporization of metals, burst reduction of metal precursors, thermal shock-induced reduction of metal precursors, and solvothermal reduction of metal precursors. Comparisons among the methods within each strategy, along with discussions, provide insights and guidance for achieving the robust synthesis of HEA nanoparticles.

Systematic Assessment of Phonon and Optical Characteristics for Gas-Source Molecular Beam Epitaxy-Grown InP1−xSbx/n-InAs Epifilms

Experimental and theoretical assessments of phonon and optical characteristics are methodically accomplished for comprehending the vibrational, structural, and electronic behavior of InP1−xSbx/n-InAs samples grown by Gas-Source Molecular Beam Epitaxy. While the polarization-dependent Raman scattering measurements revealed InP-like doublet covering optical modes (ωLOInP~350 cm−1, ωTOInP~304 cm−1) and phonons activated by disorders and impurities, a single unresolved InSb-like broadband is detected near ~195 cm−1. In InP1−xSbx, although no local vibrational (InSb:P; x → 1) and gap modes (InP:Sb; x → 0) are observed, the Raman line shapes exhibited large separation between the optical phonons of its binary counterparts, showing features similar to the phonon density of states, confirming “two-mode-behavior”. Despite the earlier suggestions of large miscibility gaps in InP1−xSbx epilayers for x between 0.02 and 0.97, our photoluminescence (PL) results of energy gaps insinuated achieving high-quality single-phase epilayers with x ~ 0.3 in the miscibility gap. Complete sets of model dielectric functions (MDFs) are obtained for simulating the optical constants of binary InP, InSb, and ternary InP1−xSbx alloys in the photon energy (0 ≤ E ≤ 6 eV) region. Detailed MDF analyses of refractive indices, extinction coefficients, absorption and reflectance spectra have exhibited results in good agreement with the spectroscopic ellipsometry data. For InP0.67Sb0.33 alloy, our calculated lowest energy bandgap E0 ~ 0.46 eV has validated the existing first-principles calculation and PL data. We feel that our results on Raman scattering, PL measurements, and simulations of optical constants provide valuable information for the vibrational and optical traits of InP1−xSbx/n-InAs epilayers and can be extended to many other technologically important materials.

Efficient Optimization of High‐Quality Epitaxial Lithium Niobate Thin Films by Chemical Beam Vapor Deposition: Impact of Cationic Stoichiometry

AbstractLithium niobate is a material of special interest for its challenging functional properties, which can suit various applications. However, high quality 200‐mm LixNb1‐xO3 thin film grown on sapphire substrate have never been reported so far which limits these potential applications. This paper reports the efficient optimization of high quality LiNbO3 thin film deposition on sapphire (001) substrate through chemical beam vapor deposition in a combinatorial configuration. With this technique, flow ratio of Li/Nb can be tuned from ≈0.25 to ≈2.45 on a single wafer. Various complementary characterizations (by means of diffraction, microscopy and spectroscopy techniques) have been performed at different areas of the film (different cationic ratios) in order to investigate the impact of the cationic stoichiometry deviation on the film properties. Close to cationic stoichiometry (LiNbO3), the epitaxial films are of high quality (single phase in spite of two in‐plane domains, low mosaicity of 0.04°, low surface roughness, refractive index and band gap close to bulk values). Deviating from the stoichiometry conditions, secondary phases are detected (LiNb3O8 for Nb‐rich flow ratios, and Li3NbO4 with partial amorphization for Li‐rich flow ratios). LiNbO3 films are of high interest for various key applications in data communications among others.

Multicolor tunable luminescence and energy transfer mechanism in Gd2O2S: Dy3+, Sm3+ phosphors

High quality single-phase multicolor emission phosphor is a prerequisite for efficient luminescence devices, but the system design and quantity preparation are still facing substantial challenges. Herein, Gd2O2S-based phosphors with high crystallinity, good dispersibility, and relatively good size uniformity were obtained by optimizing the type and components of flux based on the conventional solid-state method. By single-doping system study, the emission properties of matrix and activated ions are expounded, meanwhile the composition and co-excitation wavelength of co-doping system are designed. In the co-doping system, we mainly realized adjustable emission, interionic energy transfer, and application performance analysis. Firstly, multicolor emission in the range of yellow, orange and white was achieved through the modulation of dopant type and concentration as well as excitation wavelength. Secondly, the phenomena of spectral overlap (between Dy3+ and Sm3+), fluorescence intensity change (606 nm of Sm3+) and the monotonically decreasing fluorescence lifetime (Dy3+ at 578 nm) were evidence of energy transfer in the co-doping system. The theoretical fitting demonstrates that the energy transfer process of Dy3+→Sm3+ is primarily based on the quadrupole-quadrupole interaction mechanism. In addition, the cathodoluminescence spectra, temperature-dependent emission spectra, and magnetic properties tests have demonstrated the characteristics of multicolor adjustable emission (electron-beam excitation), excellent thermal stability, and good paramagnetic properties of the co-doping phosphors, further indicating that the Gd2O2S:Dy3+/Sm3+ system phosphors have potential as an excellent optical-magnetic bifunctional material in the fields of luminescence and bioimaging.

Multiferroic-field coupling in ultrathin nanofilm halide perovskite at room temperature

New materials with unique properties and nanostructures are essential for high-efficiency multibit devices to implement next-generation core logic and memory functions. Herein, a high-quality single-phase ultrathin nanofilm organic–inorganic hybrid perovskite nanostructure without transition metals is proposed. (C4H9NH3)2PbI2Br2 is a multifield coupling material with ferroic orders coexisting at room temperature (300 K). The domain rotation is controlled by adjusting the electric field strength using magnetoelectricity and ferroelectricity. The responsiveness and phase controllability of ferromagnetism, ferroelectricity, and piezoelectricity in ultra-thin nanofilm hybrid perovskites are successfully controlled through the external electric field induced by the coupling between the ferroic orders at room temperature. This study shows that high-quality nanostructured perovskites are suitable materials for high-efficiency multibit devices.

Epitaxial CdSe/PbSe Heterojunction Growth and MWIR Photovoltaic Detector

A novel Epitaxial Cadmium Selenide (CdSe) on Lead Selenide (PbSe) type-II heterojunction photovoltaic detector has been demonstrated by Molecular Beam Epitaxy (MBE) growth of n-type CdSe on p-type PbSe single crystalline film. The use of Reflection High-Energy Electron Diffraction (RHEED) during the nucleation and growth of CdSe indicates high-quality single-phase cubic CdSe. This is a first-time demonstration of single crystalline and single phase CdSe growth on single crystalline PbSe, to the best of our knowledge. The current-voltage characteristic indicates a p-n junction diode with a rectifying factor over 50 at room temperature. The detector structure is characterized by radiometric measurement. A 30 μm × 30 μm pixel achieved a peak responsivity of 0.06 A/W and a specific detectivity (D*) of 6.5 × 108 Jones under a zero bias photovoltaic operation. With decreasing temperature, the optical signal increased by almost an order of magnitude as it approached 230 K (with thermoelectric cooling) while maintaining a similar level of noise, achieving a responsivity of 0.441 A/W and a D* of 4.4 × 109 Jones at 230 K.

Single-phase white light material and antibiotic detection of lanthanide metal-organic frameworks.

WLEDs have been widely used in lighting and display equipment due to their energy-saving and environment-friendly advantages, but it is still a great challenge to construct high-quality single-phase white light materials for the preparation of WLEDs. In this work, three Ln-MOFs (HNU-82-84) with the same structure were synthesized by assembling rare earth ions (Tb3+, Eu3+, La3+) and 4,4',4''-nitrilotribenzoic acid (H3TCA) ligands. The structure and optical properties of the three compounds were investigated. Under the ultraviolet lamp, HNU-82-84 displays green light, red light, and blue light emission, respectively. Based on the RGB principle, aiming at the single-phase white material, the proportion of adding rare earth ions is reasonably adjusted to design and synthesize the Ln-MOF (Eu0.015Tb0.037La0.148-TCA) with CIE chromaticity coordinates of (0.319, 0.344). In addition, the WLED was prepared by Eu0.015Tb0.037La0.148-TCA and commercial LED lamps. Furthermore, HNU-82 has strong fluorescence emission and good water stability and can be used to detect nitrofurazone (NZF) and nitrofurantoin (NFT). The concentrations of the aqueous solutions of NZF and NFT had a well correlated linear relationship with the fluorescence quenching effect of HNU-82, and the detection limits were 6.60 × 10-7 mol L-1 and 4.62 × 10-7 mol L-1, respectively. Hence, HNU-82 also has potential as a fluorescent sensor for the detection of NZF and NFT in the aquatic environment.

Alternate-Target Layer-By-Layer Pulsed Laser Deposition of Epitaxial BiVO4 Thin Films

Bismuth vanadate (BiVO4) has emerged as one of the highest performing metal oxide photoelectrodes for solar energy-to-fuels applications [1, 2]. This achievement has been largely attributed to the development of high-quality synthesis techniques. Specifically, epitaxial synthetic routes to producing lattice-matched, near single-crystalline quality BiVO4 with minimal extrinsic defects have been essential to understand the fundamental and PEC properties of BiVO4 that are inaccessible by conventional bulk synthesis techniques. In addition, epitaxial synthesis may also be employed as a strategy to further improve the PEC properties of BiVO4 through, for instance, altering the band structure and enhancing the carrier dynamics by strain engineering. Hence, the ability to produce high-quality single-phase epitaxial BiVO4 films is desirable.To date, molecular beam epitaxy (MBE), chemical vapor deposition (CVD), and pulsed laser deposition (PLD) [3] have been used to fabricate epitaxial BiVO4 thin films, with PLD having the advantage of relatively simple experimental setup and material versatility. However, an oft-noted drawback in conventional PLD using single oxide targets is off-stoichiometry in the deposited films; this is especially so for BiVO4 which requires a Bi-rich compound target to achieve a stoichiometric BiVO4 film [4]. This problem is also expected in general for multinary oxides composed of elements with very different ablation properties. To alleviate the limitations of conventional PLD, we employ for the first time alternate-target layer-by-layer PLD as a more elegant approach to produce high quality epitaxial BiVO4 films. Briefly, constituent oxide targets are alternately ablated by an excimer laser (λ= 248 nm) to build the desired film one unit cell thick at a time. Stoichiometry is controlled by the number of shots corresponding to a specified laser fluence for the constituent oxide target.To demonstrate the method, we deposited epitaxial BiVO4 films onto (001)-oriented yttrium-stabilized zirconia (YSZ) using 4N-pure Bi2O3 and V2O5 targets. Films grown are single phase BiVO4 as shown by x-ray diffraction. Out-of-plane diffraction peaks indexed to BiVO4(00l) suggests epitaxy of the film onto the substrate; reciprocal space maps of the asymmetric BiVO4(208) and YSZ(204) peaks further confirm the BiVO4(001) || YSZ(001) epitaxial relationship (top figure). Rocking curves of the BiVO4 (004) peak (FWHM ~ 0.015-0.041) indicate high crystalline perfection of the BiVO4 film, almost approaching that of the YSZ substrate (FWHM ~ 0.010). Thickness dependent-rocking curve studies reveal that BiVO4 films are strained to the substrate for film thicknesses under 22 nm; above this critical thickness, film relaxation ensues. In turn, the resulting optoelectronic properties of the BiVO4 film is dictated by its relaxation state. The optical band gap narrows with film relaxation as observed with spectroscopic ellipsometry. Moreover, steady-state photoluminescence emission spectroscopy reveals a sub-bandgap state (A 2, bottom figure) associated with strained BiVO4 films, on top of a state consistent with band-to-band recombination (B1 ). A higher energy sub-bandgap state (A 1, bottom figure) develops as the film relaxes. The implications of the relaxation state on the charge carrier dynamics and photoelectrochemical properties of BiVO4 will be discussed. Figure: (top) reciprocal space maps of the asymmetric BiVO4(208) and YSZ(204) peaks; (bottom) photoluminescence emission spectra of strained and relaxed BiVO4 films.

Optimization for preparing Bi1.68Pb0.32Sr1.75Ca1.85Cu2.85O10+y powders by wet ball milling

Superconducting Bi1.68Pb0.32Sr1.75Ca1.85Cu2.85O10+y (Bi-2223) powders were prepared by a conventional solid-state reaction using hand grinding and wet ball milling. The effects of the ball milling and sintering times on the phase evolution were examined by x-ray diffraction and magnetic susceptibility measurements. Single-phase Bi-2223 powders with a superconducting transition temperature of about 108 K were optimally prepared by wet ball milling for 20 h and sintering at 867 °C for 80 h. Finding these optimal preparation conditions were crucial for mass producing high-quality single-phase Bi-2223 precursor powders with a much lower cost of energy. Furthermore, we found that ball milling led to thinner grains than hand grinding.

A neutron diffraction investigation of high valent doped barium ferrite with wideband tunable microwave absorption

The barium ferrite BaTixFe12−xO19 (x = 0.2, 0.4, 0.6, 0.8) (BFTO-x) ceramics doped by Ti4+ were synthesized by a modified sol—gel method. The crystal structure and magnetic structure of the samples were determined by neutron diffraction, and confirm that the BFTO-x ceramics were high quality single phase with sheet microstructure. With x increasing from 0.2 to 0.8, the saturation magnetization (Ms) decreases gradually but the change trend of coercivity (Hc) is complex under the synergy of the changed grain size and the magnetic crystal anisotropy field. Relying on the high valence of Ti4+, double resonance peaks are obtained in the curves of the imaginary part of magnetic conductivity (μ″) and the resonance peaks could move toward the low frequency with the increase of x, which facilitate the samples perform an excellent wideband modulation microwave absorption property. In the x = 0.2 sample, the maximum reflection loss (RL) can reach −44.9 dB at the thickness of only 1.8 mm, and the bandwidth could reach 5.28 GHz at 2 mm when RL is less than −10 dB. All the BFTO-x ceramics show excellent frequency modulation ability varying from 18 (x = 0.8) to 4 GHz (x = 0.4), which covers 81% of the investigated frequency in microwave absorption field. This work not only implements the tunable of electromagnetic parameters but also broadens the application of high-performance microwave absorption devices.

Monolayer 1T-NbSe2 as a 2D-correlated magnetic insulator.

Monolayer group V transition metal dichalcogenides in their 1T phase have recently emerged as a platform to investigate rich phases of matter, such as spin liquid and ferromagnetism, resulting from strong electron correlations. Newly emerging 1T-NbSe2 has inspired theoretical investigations predicting collective phenomena such as charge transfer gap and ferromagnetism in two dimensions; however, the experimental evidence is still lacking. Here, by controlling the molecular beam epitaxy growth parameters, we demonstrate the successful growth of high-quality single-phase 1T-NbSe2. By combining scanning tunneling microscopy/spectroscopy and ab initio calculations, we show that this system is a charge transfer insulator with the upper Hubbard band located above the valence band maximum. To demonstrate the electron correlation resulted magnetic property, we create a vertical 1T/2H NbSe2 heterostructure, and we find unambiguous evidence of exchange interactions between the localized magnetic moments in 1T phase and the metallic/superconducting phase exemplified by Kondo resonances and Yu-Shiba-Rusinov–like bound states.

The output performance of high power quality three‐phase to single‐phase AC power generation system based on open‐winding PMSG for standalone power system

A three-phase to single-phase direct AC power generation system based on the open-winding permanent magnet synchronous generator (PMSG) with the dual-inverter is proposed in this study for the standalone power system. The negative DC terminals of the dual-inverter are commonly connected, and the positive DC terminals are reconstructed as the output port of the single-phase AC power; the three-phase AC power generated by PMSG could be converted to be the high power quality single-phase AC power directly without any LC filters. Different from the traditional OW-PMSG system, zero-sequence current is employed to achieve adjustable frequency and voltage of the single-phase AC power, and the corresponding dual voltage-loop control strategy with the separate positive-sequence and zero-sequence currents regulation of PMSG is given to achieve high output performance. The effectiveness of the proposed control strategy and the output characteristics have been verified by simulation and the experiment of the prototype, and the results show that the high-quality single-phase AC power can be obtained at a wide speed range and at different load operating conditions.

Thin-film growth of MAX phases as functional materials

Abstract Layered nanolaminate ternary carbides, nitrides and carbonitrides with general formula Mn+1AXn or MAX (n = 1, 2, or 3, M is an early transition metal, A is mostly group 13 or 14 element and X is C and/or N) has revolutionized the world of nanomaterials, due to the coexistence of both ceramic and metallic nature, giving rise to exceptional mechanical, thermal, electrical, chemical properties and wide range of applications. Although several solid-state bulk synthesis methods have been developed to produce a variety of MAX phases, however, for certain applications, the growth of MAX phases, especially in its high-quality epitaxial thin-films form is of increasing interest. Here, we summarize the progress made thus far in epitaxial growth and property evaluation of MAX phase thin films grown by various deposition techniques. We also address the important future research directions to be made in terms of thin-film growth. Overall, in the future, high-quality single-phase epitaxial thin-film growth and engineering of chemically diverse MAX phases may open up interesting new avenues for next-generation technology.

Investigation on barometric and hydrostatic pressure sensing properties of Pb[(Mg1/3Nb2/3)0.7Ti0.3]O3 electro-ceramics

Two-stage solid-state reaction-based intermediate columbite phase technique has been employed to fabricate the single-phase Pb[(Mg1/3Nb2/3)0.7Ti0.3]O3 (PMN-0.3 PT) electro-ceramics. The Rietveld refinement of XRD data suggests the presence of monoclinic crystal structure with space group ‘Cm’. The bulk ceramics interior looks very flat without voids and well-defined grain boundaries, which confirm the high quality single-phase microstructure. The final elemental compositions of the material are similar to the initial compositions within the instrument's experimental error. We have investigated pressure and temperature-dependent dielectric and impedance properties to test the possible applications as a pressure transducer. A well defined square hysteresis with large polarization confirms the high quality ferroelectric and piezoelectric properties. For the first time, we have studied the pressure sensing properties of PMN-0.3 PT ceramic in the range 25–250 kPa in barometric pressure using dead weights and 10–50 MPa hydraulic pressure (oil medium). The ceramic demonstrates a gradual change in capacitance as well as in capacitive reactance, with % sensitivity of 0.10 MPa−1 in the Hydraulic pressure range (10–50 MPa), and with % sensitivity of 0.02 kPa−1 in the Barometric pressure range (25–250 kPa). These results demonstrate the suitability of PMN-0.3 PT ceramic as a pressure transducer.

A High Power, High Quality Single-Phase AC-DC Converter for Wireless Power Transfer Applications

A High Power, High Quality Single-Phase AC-DC Converter for Wireless Power Transfer Applications

Fabrication of Illumination-Dependent Cu/p-Si Schottky Barrier Diodes by Sandwiching MoO3 Nanoplates as an Interfacial Layer via JNSP Technique

Highly oriented ultrathin MoO3 nanoplate thin films have been synthesized on a large scale using a low-cost spray pyrolysis technique at different substrate temperatures (350°C, 400°C, 450°C, and 500°C). High-quality single-phase orthorhombic α-MoO3 nanoplate film was observed by x-ray diffraction analysis. The surface morphology of the coated films was analyzed by field-emission scanning electron microscopy, revealing two different surface structures, viz. nanorods and nanoplates. Under atomic force microscopy, the surface roughness of the films was found to decrease with increasing substrate temperature. The optical properties of the α-MoO3 nanoplate thin films were analyzed by ultraviolet–visible and photoluminescence spectroscopy. The optical bandgap varied from 2.8 eV to 3.2 eV, recording a red-shift in the emission, with increasing substrate temperature from 350°C to 500°C. The electrical conductivity was also found to increase linearly with increasing substrate temperature. Various photodiode parameters such as ideality factor (n), barrier hight (ФB), photo sensitivity (PS), resistivity (R), quantum efficiency (QE) and detectivity (D*) were calculated for different light intensities from 0 mW/cm2 to 120 mW/cm2 based on the I–V characteristic. The diode fabricated at 500°C showed a remarkably high photosensitivity and specific detectivity of 610.51% and 1.149 × 1011 Jones when measured at 120 mW/cm2.

Low resistance at LiNi1/3Mn1/3Co1/3O2 and Li3PO4 interfaces

We report the low resistance observed at the interface of LiNi1/3Mn1/3Co1/3O2 (NMC) and Li3PO4. First, we show the deposition of high-quality single-phase NMC (001) epitaxial thin films on Al2O3 (0001) substrates using pulsed laser deposition. Controlling the oxidation states of the three transition metals in NMC films is crucial for stable battery operation. However, in general, it is very difficult to simultaneously control the oxidation states of three elements in vacuum deposition processes. Tuning the oxygen partial pressure and temperature during deposition led to the growth of NMC thin films with ideal oxidation states (Ni2+, Mn4+, and Co3+), as confirmed using bulk-sensitive x-ray excited optical luminescence. Next, using the NMC epitaxial thin films, we prepared solid-state batteries that demonstrated stable operation and very low resistance at the solid electrolyte/electrode interfaces. These results provide insight into the fabrication of multi-transition-metal electrode thin film materials, which are important for investigating the mechanisms of lithium battery operation. Furthermore, the low interface resistance indicates that Li3PO4 and oxide electrode materials form very stable low-resistance interfaces.

Peculiarities of the Crystal Structure and Texture of Isotropic and Anisotropic Polycrystalline Hexagonal Ferrites BaFe12O19 Synthesized by Radiation-Thermal Sintering

In this work the crystal structure and texture of isotropic and anisotropic polycrystalline hexagonal ferrites BaFe12O19 obtained by the method of radiation-thermal sintering (RTS) is studied using X-ray diffraction and X-ray phase analysis. Crude blanks of both isotropic and anisotropic hexaferrites are obtained by the standard method of ceramic technology from the same raw material (Fe2O3 and BaCO3 of the analytical grade brand) and on the same equipment with the only difference being that the anisotropic blanks were pressed in the magnetic field H = 10 kOe. For sintering raw billets, a linear electron accelerator ILU-6 (electron energy Ee = 2.5 MeV) is used (Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences). The samples are sintered in air for one hour at 1200, 1250, 1300, and 1350°C. It is shown for the first time that high-quality single-phase isotropic and anisotropic hexaferrites BaFe12O19 can be obtained from raw blanks of a ferritized charge using the RTS technology. The properties of the crystal structure and texture of the obtained objects of the research are described. It is established for the first time that the dependence of the pref.orient.o1 predominant orientation of the crystal texture parameter on the degree of the magnetic texture f in polycrystalline hexagonal barium ferrites of type M is described by the expression pref.orient.o1 = –0.005f + 0.6886.

Nanostructured Au(111)/Oxide Epitaxial Heterostructures with Tailoring Plasmonic Response by a One-Step Strategy

In this work, we present a strategy for developing epitaxial incommensurate nanostructured Au/oxide heterostructures with tunable plasmonic response. Previously, high-quality single-phase and singl...