Новые публикации

https://doi.org/10.1021/acs.chemmater.4c00514

Halide double perovskites like Cs₂NaBiCl₆ are good host materials for luminescent dopants like Mn²⁺. The nature of photoluminescence (PL) depends on the local structure around the dopant ion, and doping may sometimes influence the global structure of the host. Here, we unveil the correlation between the temperature-induced (global) structural phase transition of Mn²⁺-doped Cs₂NaBiCl₆ with the local structure and PL of the Mn²⁺ dopant. X-ray diffraction analysis shows Mn²⁺-doped Cs₂NaBiCl₆ is in a cubic (Fm3m) phase between 300 and 110 K, below which the phase changes to tetragonal (I4/mmm), which persists at least until 15 K. The small (∼1%) doping amount does not alter the phase transition behavior of Cs₂NaBiCl₆. Importantly, the phase transition does not influence the Mn²⁺ d-electron PL. The PL peak energy, intensity, spectral width, and lifetime do not show any signature of the phase transition between 300–6 K. The hyperfine splitting in temperature-dependent electron paramagnetic spectra of Mn²⁺ ions also remain unchanged across the phase transition. These results suggest that the global structural phase transition of the host does not influence the local structure and emission property of the dopant Mn²⁺ ion. This structure–property insight might be explored for other transition-metal- and lanthanide-doped halide double perovskites as well. The stability of dopant emission regardless of the structural phase transition bodes well for their potential applications in phosphor-converted light emitting diodes.

https://doi.org/10.1134/S0031918X23602883

The distribution of Co²⁺ ions over sublattices and structurally nonequivalent positions in the unit cell of the crystal lattice of a single crystal of lithium gallium spinel Li_0.5Ga_2.5O₄ is shown. This distribution determines the properties of both mono- and nanocrystalline substances. The distribution is obtained by a special technology and is manifested in the electron paramagnetic resonance (EPR) spectra. The distribution of Co²⁺ ions depends on the structural and magnetic nonequivalence. The structural and magnetic nonequivalence causes a multiminimum behavior of the crystal field potential in the unit cells of single crystals at the locations of Co²⁺ ions. The Co²⁺ ions are found in complexes with tetrahedral and octahedral oxygen ions. Three types of EPR spectra of Co²⁺ ions have been found and investigated. The [Math Processing Error]Cotetr2+ spectrum is attributed to the Co²⁺ ion, which replaces the Ga³⁺ ion located in a tetrahedral oxygen environment. The spectrum of the [Math Processing Error]Cooct2+ ion located in the crystal field with axial symmetry belongs to the Co²⁺ ion replacing the Li⁺ ion located in an octahedral oxygen environment. The spectrum of the [Math Processing Error]Cooct2+ ion located in a low symmetry crystal field belongs to the Co²⁺ ion replacing the Ga³⁺ ion located in an octahedral oxygen environment. The nearest cationic environment of the ion creates rhombic distortions due to the different valence numbers of Li⁺ and Ga³⁺. The results of studying the angular dependences of the spectra show the presence of four and twelve magnetically nonequivalent positions in the unit cells.

Журн. СФУ. Сер. Матем. и физ., 17:2 (2024), 162–168

Предложена новая конструкция ВТСП ограничителя мощности с двумя рабочими полосами. Ограничитель содержит два микрополосковых полосно-пропускающих фильтра. Каждый фильтр состоит из двух четвертьволновых резонаторов, которые связаны между собой через составной полуволновый резонатор, содержащий пленку из высокотемпературного сверхпроводника. Макет устройства в открытом режиме имеет ширины рабочих полос пропускания 10% и 11% с центральными частотами 1.48 ГГц и 2.03 ГГц. Минимальные вносимые потери составили 1.9 дБ и 1.7 дБ для НЧ- и ВЧ-каналов соответственно. Передаточные характеристики устройства были исследованы до уровня СВЧ-мощности 3.15 Вт.

https://doi.org/10.1080/1536383X.2024.2338524/

A fullerene mixture was enriched with endohedral metallofullerenes (EMF) using Lewis acid (TiCl₄), which took 22 min, whereas the standard method requires about 8 h. An algorithm for assessing small-area chromatographic peaks has been proposed, which has improved the accuracy of determination. For example, the area of the C₈₄ peak was 4.24% using the developed program, while the use of chromatograph software estimated the area of this peak to be 1.78%.

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TiO2 photonic crystal nanostructure films are anodic synthesized with pulsed and stepwise voltage changes. The obtained photonic structures were activated by cyclic voltammetry in 0.5M Na2SO4. The photoelectrochemical activity of the electrodes was studied in the water splitting reaction in the wavelength range 360–700 nm. Activation leads to a change in the band gap energy, a red shift in the IPCE spectrum and an increase in its values in the studied wavelength range

https://doi.org/10.1134/S1063774523601296

MnBi₂Te₄, Mn(Bi,Sb)₂Te₄, and MnBi₂Te₄(Bi₂Te₃)_m (m ≥ 1) are assigned to magnetic topological insulators. Successful application of these materials in nanoelectronic devices calls for comprehensive investigation of their electronic structure and magnetic properties in dependence of the Bi/Sb atomic ratio and the number m of Bi₂Te₃ blocks. The magnetic properties of the surface of MnBi₂Te₄, MnBi₄Te₇, and Mn(Bi1−�Sb_x)₂Te₄ compounds (x = 0.43 and 0.32) have been studied using the magneto-optical Kerr effect. It is shown that the temperatures of magnetic transitions on the surface and in the bulk of MnBi₄Te₇ and Mn(Bi, Sb)₂Te₄ differ significantly.

https://doi.org/10.1016/B978-0-32-395195-1.00012-0

We consider dielectric cavities whose radiation space is restricted by two parallel metallic planes. The TE solutions of the Maxwell's equations of the system are equivalent to the solutions of periodical arrays of dielectric cavities. The system readily allows to achieve bound states in the continuum (BICs) of any type, including topological BICs that depends on the position and orientation of the cavities relative to the planes. This facilitates experimental studies immensely compared to infinite arrays of the cavities. We show the effect of merging topologically protected BICs, which pushes the square asymptotic of the Q-factor to the power degree of 4 or even 6.

https://doi.org/10.1134/S1061933X23601294

Due to their unique properties, organosols of silver nanoparticles are widely used in optical and semiconductor devices, to produce electrically and thermally conductive films, as catalysts, antibacterial materials, etc. This work proposes a simple and highly productive method for the preparation of silver organosols, which have a metal concentration as high as 1800 g/L and contain spherical nanoparticles with low polydispersity and a median size of 9.1 nm. The method consists in the initial preparation of silver nanoparticle hydrosols with a concentration of higher than 30 g/L followed by the transfer of the NPs into an organic phase of o-xylene. A set of physical research methods has been employed to study the regularities of the extraction of silver nanoparticles with o-xylene in the presence of cetyltrimethylammonium bromide (CTAB) and ethanol and to determine the optimal process conditions, under which the extraction degree is as high as 62.5%. It has been found that bromine anions contained in CTAB molecules cause the aggregation of some amount of silver nanoparticles with the formation of silver metal sediment in the aqueous phase. According to X-ray photoelectron spectroscopy data, the sediment contains bromide ions (up to 4 at %) on the particle surface. Organosols synthesized under optimal conditions are stable for more than 7 months and withstand repeated cycles of drying and redispersing. Silver organosols have been used to obtain metal films with an electrical conductivity of about 68 500 S/cm, which increases to 412 000 and 509 500 S/cm (87.8% of the electrical conductivity of bulk silver) after thermal treatment at 150 and 250°C, respectively.

https://doi.org/10.1134/S0021364023604244

The magnetic structure of Fe₅O₆ is studied using a combination of the group-theoretical analysis and DFT + U calculations of the electronic spectrum. The calculations are performed for the magnetic k = (0, 0, 0) vector. The magnetic ground state corresponds to the orthogonal ordering of two magnetic subsystems:  the magnetic moments of Fe²⁺/Fe³⁺ ions located at the octahedral sites (slabs of octahedra) are directed along the c axis and are antiferromagnetically ordered, whereas the magnetic moments of Fe²⁺ ions in trigonal prisms forming one-dimensional chains are directed along the b axis and are antiferromagnetically coupled along the c axis. The formation of a nonzero antiferromagnetic component of magnetic moments in the slabs of octahedra directed along the b axis is caused by the effect of magnetic chains on the three-dimensional magnetic structure.

https://doi.org/10.1021/acsmaterialslett.4c00263

The discovery of high-efficiency Mn⁴⁺-activated fluoride red phosphors with short excited-state lifetimes (ESLs) is urgent and crucial for high-quality, wide-color-gamut display applications. However, it is still a great challenge to design target phosphors with both short ESL and high luminescence efficiency. Herein, we propose an efficient machine learning approach based on a small dataset to establish the ESL prediction model, thereby facilitating the discovery of new Mn⁴⁺-activated fluorides with short ESLs. Such a model can not only accurately predict the ESLs of Mn⁴⁺ in fluorides but also quantify the impact of structure features on ESLs, therefore elucidating the “structure-lifetime” correlations. Guided by the correlations, two new Mn⁴⁺-doped tetramethylammonium (TMA)-based hybrid fluorides (TMA)₂BF₆:Mn⁴⁺ (B = Sn or Hf) with both short ESLs (τ ≤ 3.7 ms) and high quantum efficiencies (internal QEs > 92%, external QEs > 55%) have been discovered successfully. A prototype displayer with excellent performance (∼124% National Television Standards Committee (NTSC) color gamut) is assembled by employing a (TMA)₂SnF₆:Mn⁴⁺-based white Mini-LED backlight module, demonstrating its practical prospects in high-quality displays. This work not only brings promising candidates for Mn⁴⁺-doped fluoride phosphors but also provides a valuable reference for accelerating the discovery of new promising phosphors.

https://doi.org/10.1134/S0030400X23060024

Iron borates NdFe₃(BO₃)₄ and SmFe₃ (BO₃)₄ activated with 1% erbium, with ahuntite structure (space symmetry group R32) were investigated by the method of erbium spectroscopic probe. From an analysis of the temperature dependence of the transmission spectra in the region of the ⁴I_15/2 → ⁴1_13/2 transition in the Er³⁺ ion, it was found that both studied compounds order antiferromagnetically at T_N ≈ 33 K into an easy-plane magnetic structure. No other phase transitions were found.

https://doi.org/10.1134/S0030400X23060127

This work presents information on the growth and spectroscopic study of single crystals of copper metaborate doped with nickel Cu_1–xNi_xB₂O₄ (x = 0.05, 0.1). In the absorption spectra of both crystals, satellites related to Cu centers distorted by impurity Ni atoms were observed near the lines of zero phonon transitions. Polarization studies in the isotropic ab-plane of the tetragonal crystal Cu_1–xNi_xB₂O₄ show the presence of linear magnetic dichroism in the magnetically ordered state, which was previously observed both in manganese-doped and undoped copper metaborates CuB₂O₄. The temperature of magnetic phase transitions into the collinear antiferromagnetic and into helicoidal structures, T_N = 19.1 K and T * = 8.6 K, respectively, were determined from the temperature dependence of the dichroic signal.

https://doi.org/10.1134/S0030400X23070081

The Raman spectra of four crystals of TbFe_3–xGa_x(BO₃)₄ solid solutions (x from 0 to 0.54) were studied in the temperature range from 8 to 350 K. The temperatures of structural phase transitions were determined. The observed spectral behavior is characteristic to condensation and restoration of soft modes. Soft modes are associated with a structural phase transition from the R32 phase to the P3₁21 phase. The Compositions-Temperature phase diagram was constructed.

https://doi.org/10.3103/S8756699023060134

A method for the determination of pore orientation in metal-organic framework structures by polarized Raman spectra is proposed. The method involves sensitivity of the line intensity of Raman scattering to the geometry of propagation in a crystal. The operability of the method is shown by DUT-8 (Ni, Co) crystals. The obtained results are interpreted based on analysis of symmetry and direction of vibrations within periodic calculations of the electron density functional theory. The simultaneous approach allowed us to describe the vibrations and to find the principal crystal orientation collinear to the pore direction. The information on the pore orientation is necessary for problems of adsorption and design of complex multicomponent materials based on metal-organic framework.

https://doi.org/10.1016/j.jssc.2024.124693

The structure and phases formed in Sn/Co thin films are interesting both from the solid-state chemistry point of view and due to applications of such a metallic bilayer. The phases forming in thin films Sn/Co obtained by thermal vacuum evaporation on two different substrates SiO₂ and MgO(100) at different annealing temperatures have been studied. Annealing above 110°С results in intermetallics formation in the films. The hcp-cobalt is grown in the films on SiO₂ substrate, and the fcc-Co is observed on MgO(100) substrate. It is found that the stable α-Co₃Sn₂ intermetallic is formed at higher annealing temperature in film on MgO(100) substrate. We show that transformations related to mass transfer in the Sn/Co bilayers were up to 500°С and were finished upon reaching the thermodynamically equilibrium phase composition at this temperature.

https://doi.org/10.1134/S0030400X23020121

Experimental and theoretical study of submillimeter (terahertz) spectroscopic and magnetic properties of the rare-earth aluminum borate HoAl₃(BO₃)₄ were performed at temperatures 3–300K. In the transmittance spectra a number of resonance lines were detected at frequencies 2–35 cm^–1 for different radiation polarizations. These modes were identified as transitions between the lower levels of the ground multiplet of the Ho³⁺ ion split by the crystal field, including both transitions from the ground state to the excited ones and transitions between the excited states. The established excitation conditions of the observed modes and the simulation of the spectra made it possible to separate the magnetic and electric dipole transitions and to determine the energies of the corresponding states, their symmetry, and the matrix elements of the transitions. Low-frequency lines that do not fit into the established picture of the electron states of Ho³⁺ were also found; these lines, apparently, correspond to the ions with the distorted by defects local symmetry of the crystal field.

https://doi.org/10.1134/S0021364023603962

Nonlinear phenomena similar to the Belousov–Zhabotinsky reaction (autocatalytic oscillations of the population of high-spin and low-spin multielectron states of a transition metal ion) in open systems with spin crossover near bistability are considered. The conditions for possible experimental observation of autocatalytic oscillations of the magnetization in magnetically ordered systems with spin crossover are analyzed.

https://doi.org/10.1103/PhysRevE.109.L032107

We analyze the stationary current of Bose particles across the Bose-Hubbard chain connected to a battery, focusing on the effect of interparticle interactions. It is shown that the current magnitude drastically decreases as the strength of interparticle interactions exceeds the critical value which marks the transition to quantum chaos in the Bose-Hubbard Hamiltonian. We found that this transition is well reflected in the nonequilibrium many-body density matrix of the system. Namely, the level-spacing distribution for eigenvalues of the density matrix changes from Poisson to Wigner-Dyson distributions. With the further increase of the interaction strength, the Wigner-Dyson spectrum statistics change back to the Poisson statistics which now marks fermionization of the Bose particles. With respect to the stationary current, this leads to the counter-intuitive dependence of the current magnitude on the particle number.

https://doi.org/10.1103/PhysRevB.109.125139

Based on the Wilson's criterion metal/insulator, extended to materials with strong electronic correlations, we have identified a specific class of the materials, which is not associated with their usual classification into Mott-Hubbard and charge transfer dielectrics. The local symmetry of these materials leads to the disappearance of quasiparticle states (so-called first removal or first extra states) in the Hubbard gap. It is especially unusual for doped materials, in which quasiparticles, being charge carriers, can disappear or appear under external factors without the Mott transition being achieved. In this work, we introduce the so-called “quasiparticle transparency”, and provide specific experiments to identify materials with the low quasiparticle transparency. A number of examples of such materials with a spin crossover under high pressure, showing the Jahn-Teller nature, are considered.

https://doi.org/10.3389/fphy.2024.1322162

In the context of the 21st century and the fourth industrial revolution, the substantial proliferation of data has established it as a valuable resource, fostering enhanced computational capabilities across scientific disciplines, including physics. The integration of Machine Learning stands as a prominent solution to unravel the intricacies inherent to scientific data. While diverse machine learning algorithms find utility in various branches of physics, there exists a need for a systematic framework for the application of Machine Learning to the field. This review offers a comprehensive exploration of the fundamental principles and algorithms of Machine Learning, with a focus on their implementation within distinct domains of physics. The review delves into the contemporary trends of Machine Learning application in condensed matter physics, biophysics, astrophysics, material science, and addresses emerging challenges. The potential for Machine Learning to revolutionize the comprehension of intricate physical phenomena is underscored. Nevertheless, persisting challenges in the form of more efficient and precise algorithm development are acknowledged within this review.

https://doi.org/10.1134/S1061933X23601075

Layered two-dimensional materials, whose properties dramatically differ from their bulk precursors, are of great theoretical and applied importance. Recently, a layered 2D material, an analog of a natural mineral, valleriite, in which quasi-monoatomic Cu−Fe−S sheets alternate with brucite-like ones, has been prepared using a simple hydrothermal synthesis procedure. The features of the electronic structure of these materials make it possible to propose them as new materials for a wide field of applications such as (electro)photocatalysis, high-capacity batteries, etc. In this work, nanocomposite materials have been prepared via immobilization of gold nanoparticles (AuNPs) from citrate hydrosols on the surface of the synthesized valleriites having different compositions of hydroxide layers, which control the surface charge density. According to X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive X-ray microanalysis (EDX), and selected area electron diffraction (SAED) data, AuNPs are immobilized on valleriite nanoflakes, which have lateral sizes of 150–200 nm and thicknesses of several tens of nanometers, as isolated metal nanoparticles with an average diameter of 11 nm. A small amount of aggregates indicates a high affinity of AuNPs for the valleriite surface. The amounts of immobilized gold are the same on all studied valleriites (~0.2%). This finding may be related to the simultaneous sorption of free citrate ions from the AuNP hydrosols, with these ions, according to zeta potential measurements, charging the surfaces of all studied valleriite samples to nearly the same negative value of –40 mV. According to the XPS data, the AuNPs immobilization markedly decreases the magnesium and oxygen contents on the surfaces of the synthesized valleriites due to the partial degradation/dissolution of the brucite layer. In addition, the amount of Fe³⁺ ions bound to OH groups decreases with a simultaneous increase in the fraction of Fe³⁺–O species. The TEM data have confirmed the preservation of the layered structure of valleriites after the immobilization of AuNPs.

https://doi.org/10.1016/j.optmat.2024.115232

The modulation and spectral characteristics of self-organized ensembles of nematic domains with the disclination lines non-aligned and aligned in a magnetic field have been studied using an electric field. The obtained experimental voltage dependences of the light transmission agree well with the dependences calculated using the model considerations. These dependences have been compared with the electro-optical characteristics of a homogeneous planar nematic layer. The amplitude component of the optical transmission determined by light scattering and the oscillating component caused by the phase modulation have been examined. The effect of the spectral dispersion of transmission on the electro-optical characteristics of domain ensembles has been evaluated.

https://doi.org/10.1016/j.physc.2024.1354486

Porosity affects the properties of high-T_c superconductors and can improve their performance by enhancing oxygenation, cryocooling, etc. Among other factors, the presence of pores plays a significant role in the process of magnetic flux trapping. Relationships with the porosity manifest in the irreversibility field, the full penetration field, and the remnant magnetization of the samples. To account for the effect of porosity on the trapped magnetic flux into type-II superconductors, a simple toy model is suggested. Generally, as the porosity increases, the trapped flux and related parameters tend to diminish. However, in the case of microscopic samples, porosity can enhance magnetic flux trapping.

 https://doi.org/10.1002/adom.202303235

Far-red (FR) region (beyond 700 nm) lighting sources possess special potential for plant lighting. However, it remains a challenge to obtain high-performance Cr³⁺-doped FR phosphors. This study developed a FR phosphor, Ca_1.8Mg_1.2Al₂Ge₃O₁₂:Cr³⁺ (CMAGG: Cr³⁺), using the cation substitution strategy. Under 438 nm blue light excitation, the phosphors display FR emission centered at 720 nm with a full width at half maximum (FWHM) of 91 nm. Benefit from the favorable match with the FR phytochrome (P_fr), the phosphor is combined with InGaN blue light chips to create a FR phosphor-converted light-emitting diode (pc-LED), which is used in Italian lettuce growth experiments and it results shown in a 15% increase in fresh weight and a 6.5% increase in dry weight. Notably, supplemental FR light modulated its growth morphology. The results of this study will be useful for further research on novel Cr³⁺-doped FR phosphors to meet the precise spectral requirements for plant growth.

https://doi.org/10.1021/acs.inorgchem.3c04140

Optical thermometry has gained significant attention due to its remarkable sensitivity and noninvasive, rapid response to temperature changes. However, achieving both high absolute and relative temperature sensitivity in two-dimensional perovskites presents a substantial challenge. Here, we propose a novel approach to address this issue by designing and synthesizing a new narrow-band blue light-emitting two-dimensional perovskite named (C₈H₁₂NO₂)₂PbBr₄ using a straightforward solution-based method. Under excitation of near-ultraviolet light, (C₈H₁₂NO₂)₂PbBr₄ shows an ultranarrow emission band with the full width at half-maximum (FWHM) of only 19 nm. Furthermore, its luminescence property can be efficiently tuned by incorporating energy transfer from host excitons to Mn²⁺. This energy transfer leads to dual emission, encompassing both blue and orange emissions, with an impressive energy transfer efficiency of 38.3%. Additionally, we investigated the temperature-dependent fluorescence intensity ratio between blue emission of (C₈H₁₂NO₂)₂PbBr₄ and orange emission of Mn²⁺. Remarkably, (C₈H₁₂NO₂)₂PbBr₄:Mn²⁺ exhibited maximum absolute sensitivity and relative sensitivity values of 0.055 K^–1 and 3.207% K^–1, respectively, within the temperature range of 80–360 K. This work highlights the potential of (C₈H₁₂NO₂)₂PbBr₄:Mn²⁺ as a promising candidate for optical thermometry sensor application. Moreover, our findings provide valuable insights into the design of narrow-band blue light-emitting perovskites, enabling the achievement of single-component dual emission in optical thermometry sensors.

DOI: 10.1109/TGRS.2023.3340693

This article is the second in a series evaluating the effect of dielectric relaxation processes on the relatively effective complex dielectric permittivity (RCP) of soils. Part II is based on the results of experimental measurements in the frequency range 10 kHz to 8–20 GHz. The broadband dielectric spectrum model includes the high-frequency part as a model of the dielectric mixture and the relaxation part as the sum of three relaxation processes modeled by the Debye and Cole–Cole formulas. For modeling the high-frequency part of the spectrum, the Dobson and Mironov models were considered as possible options. As stated in Part I, the influence of relaxation processes on the imaginary part of the RCP extends up to frequencies of units of gigahertz. The increase in the imaginary part in these models was compensated by unrealistically high values of the specific electrical conductivity of free and bound water. We examined the correspondence of these models to experimental data at frequencies above 2–5 GHz, assuming that the conductivity of bound and free water is zero. The parameters of relaxation processes were found while solving the least-square optimization problem using the technique for determining the continuous distribution of relaxation times (DRTs). Found process parameters depend on the content of clay, organic carbon, and moisture of the samples. The more clay is in the soil, the greater the strength of these processes is. The influence of organic carbon with the conditions being equal consists in the reduction of the real and imaginary parts of RCP.

https://doi.org/10.3390/molecules29040848

Aptamers are currently being investigated for their potential to improve virotherapy. They offer several advantages, including the ability to prevent the aggregation of viral particles, enhance target specificity, and protect against the neutralizing effects of antibodies. The purpose of this study was to comprehensively investigate an aptamer capable of enhancing virotherapy. This involved characterizing the previously selected aptamer for vaccinia virus (VACV), evaluating the aggregation and molecular interaction of the optimized aptamers with the recombinant oncolytic virus VV-GMCSF-Lact, and estimating their immunoshielding properties in the presence of human blood serum. We chose one optimized aptamer, NV14t_56, with the highest affinity to the virus from the pool of several truncated aptamers and built its 3D model. The NV14t_56 remained stable in human blood serum for 1 h and bound to VV-GMCSF-Lact in the micromolar range (Kd ≈ 0.35 μM). Based on dynamic light scattering data, it has been demonstrated that aptamers surround viral particles and inhibit aggregate formation. In the presence of serum, the hydrodynamic diameter (by intensity) of the aptamer–virus complex did not change. Microscale thermophoresis (MST) experiments showed that NV14t_56 binds with virus (EC50 = 1.487 × 10⁹ PFU/mL). The analysis of the amplitudes of MST curves reveals that the components of the serum bind to the aptamer–virus complex without disrupting it. In vitro experiments demonstrated the efficacy of VV-GMCSF-Lact in conjunction with the aptamer when exposed to human blood serum in the absence of neutralizing antibodies (Nabs). Thus, NV14t_56 has the ability to inhibit virus aggregation, allowing VV-GMCSF-Lact to maintain its effectiveness throughout the storage period and subsequent use. When employing aptamers as protective agents for oncolytic viruses, the presence of neutralizing antibodies should be taken into account.

DOI https://doi.org/10.1039/D3DT04299E

Most known mixed manganites containing rare-earth elements demonstrate a pronounced charge ordering (CO) state below room temperature. The behavior of the magnetic susceptibility and electronic magnetic resonance of polycrystalline Pr_1−xSr_xMnO₃/YSZ (x = 0.2 and x = 0.4) films without a pronounced texture indicates the formation of the CO phase in the samples at temperatures close to and above room temperature. Moreover, this phase manifests itself with a typical sign of martensitic transformation. The same phenomenon has been traced for textured polycrystalline La_0.7Sr_0.3MnO₃/YSZ films. Electron microscope data indicate the presence of internal strain within the films, which is probably responsible for the formation of the CO phase. It is assumed that the reasons for the appearance of such strain include the crystallite size and the boundary between them. The results obtained provide the basis for the development of new research and technological tasks for the generation of the high-temperature CO state in various polycrystalline rare-earth manganites, since this state contributes to the manifestation of interesting magnetocaloric, magnetoelectric and multiferroic properties. In addition, recent data has opened up new opportunities for studying the strain-induced phenomena in such materials.

https://doi.org/10.1016/j.cjph.2023.11.030

Vortex relaxation has been studied in a microsized HTS with various distributions of artificial pinning in the form of submicro-holes. It has been shown that, in some cases, for a superconductor with dimensions up to several micrometers, the time dependences of the trapped magnetic field do not correspond with the collective creep model. The dependences of the trapped-field relaxation rate and vortex activation energy on the magnetizing field (up to 0.5 T) and temperature (up to 50 K) have been obtained. It has been shown that the presence of submicro-holes slightly increases the relaxation rate, mainly due to the decrease in the number of random nanosized pinning centers.

https://doi.org/10.1016/j.chemphys.2024.112257

We present first study of magnetic circular dichroism (MCD) spectra of Ho³⁺ ion in C_4v local symmetry, which it has in fluorite Na_0.4Ho_0.6F_2.2. Optical absorption and MCD spectra were studied in this single crystal in the region of ⁵I₈→ ⁵F₃, ⁵F₂, ³K₈ and ⁵G₅ transitions in the temperature range 3.6–––90 K. It was revealed, that number of transitions observed in the MCD and absorption spectra coincides with the number of transitions only from the doublet E state to singlet excited states. The E-E type transitions are not active in MCD, but they are not observed in the absorption spectra either. Paramagnetic magneto-optical activities (MOA) of the absorption bands and their temperature dependences were measured and interpreted with the help of the theory based on the nature of f-f transitions allowance. The MCD spectra were also analyzed in approximation of the �,±�� wave functions of the free atom. It was shown in particular, that the lowest initial state of the transitions observed at T > 10 K had M_J = 7, but this is not the lowest state of the holmium ion in the crystal. A little lower there is a quasi-doublet with M_J = 8 and, accordingly, with a higher magneto-optical activity of transitions from it. However, the intensity of transitions from this state is low.