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The development of the new generation of non-volatile high-density ferroelectric memory requires the utilization of ultrathin ferroelectric films. The most promising candidates are polycrystalline-doped HfO2 films because of their perfect compatibility with silicon technology and excellent ferroelectric properties. However, the remanent polarization of HfO2 films is known to degrade when their thickness is reduced to a few nanometers. One of the reasons for this phenomenon is the wake-up effect, which is more pronounced in the thinner the film. For the ultrathin HfO2 films, it can be so long-lasting that degradation occurs even before the wake-up procedure is completed. In this work, an approach to suppress the wake-up in ultrathin Hf0.5Zr0.5O2 films is elucidated. By engineering internal built-in fields in an as-prepared structure, a stable ferroelectricity without a wake-up effect is induced in 4.5 nm thick Hf0.5Zr0.5O2 film. By analysis of the functional characteristics of ferroelectric structures with a different pattern of internal built-in fields and their comparison with the results of in situ piezoresponse force microscopy and synchrotron X-ray micro-diffraction, the important role of built-in fields in ferroelectricity of ultrathin Hf0.5Zr0.5O2 films as well as the origin of stable ferroelectric properties is revealed.

The nanosecond speed of information writing and reading is recognized as one of the main advantages of next-generation non-volatile ferroelectric memory based on hafnium oxide thin films. However, the kinetics of polarization switching in this material have a complex nature, and despite the high speed of internal switching, the real speed can deteriorate significantly due to various external reasons. In this work, we reveal that the domain structure and the dielectric layer formed at the electrode interface contribute significantly to the polarization switching speed of 10 nm thick Hf0.5Zr0.5O2 (HZO) film. The mechanism of speed degradation is related to the generation of charged defects in the film which accompany the formation of the interfacial dielectric layer during oxidization of the electrode. Such defects are pinning centers that prevent domain propagation upon polarization switching. To clarify this issue, we fabricate two types of similar W/HZO/TiN capacitor structures, differing only in the thickness of the electrode interlayer, and compare their ferroelectric (including local ferroelectric), dielectric, structural (including microstructural), chemical, and morphological properties, which are comprehensively investigated using several advanced techniques, in particular, hard X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electron beam induced current technique.

The development of the new generation of non-volatile high-density ferroelectric memory requires the utilization of ultrathin ferroelectric films. The most promising candidates are polycrystalline-doped HfO[sub.2] films because of their perfect compatibility with silicon technology and excellent ferroelectric properties. However, the remanent polarization of HfO[sub.2] films is known to degrade when their thickness is reduced to a few nanometers. One of the reasons for this phenomenon is the wake-up effect, which is more pronounced in the thinner the film. For the ultrathin HfO[sub.2] films, it can be so long-lasting that degradation occurs even before the wake-up procedure is completed. In this work, an approach to suppress the wake-up in ultrathin Hf[sub.0.5] Zr[sub.0.5] O[sub.2] films is elucidated. By engineering internal built-in fields in an as-prepared structure, a stable ferroelectricity without a wake-up effect is induced in 4.5 nm thick Hf[sub.0.5] Zr[sub.0.5] O[sub.2] film. By analysis of the functional characteristics of ferroelectric structures with a different pattern of internal built-in fields and their comparison with the results of in situ piezoresponse force microscopy and synchrotron X-ray micro-diffraction, the important role of built-in fields in ferroelectricity of ultrathin Hf[sub.0.5] Zr[sub.0.5] O[sub.2] films as well as the origin of stable ferroelectric properties is revealed.

The nanosecond speed of information writing and reading is recognized as one of the main advantages of next-generation non-volatile ferroelectric memory based on hafnium oxide thin films. However, the kinetics of polarization switching in this material have a complex nature, and despite the high speed of internal switching, the real speed can deteriorate significantly due to various external reasons. In this work, we reveal that the domain structure and the dielectric layer formed at the electrode interface contribute significantly to the polarization switching speed of 10 nm thick Hf[sub.0.5] Zr[sub.0.5] O[sub.2] (HZO) film. The mechanism of speed degradation is related to the generation of charged defects in the film which accompany the formation of the interfacial dielectric layer during oxidization of the electrode. Such defects are pinning centers that prevent domain propagation upon polarization switching. To clarify this issue, we fabricate two types of similar W/HZO/TiN capacitor structures, differing only in the thickness of the electrode interlayer, and compare their ferroelectric (including local ferroelectric), dielectric, structural (including microstructural), chemical, and morphological properties, which are comprehensively investigated using several advanced techniques, in particular, hard X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electron beam induced current technique.

The nanosecond speed of information writing and reading is recognized as one of the main advantages of next-generation non-volatile ferroelectric memory based on hafnium oxide thin films. However, the kinetics of polarization switching in this material have a complex nature, and despite the high speed of internal switching, the real speed can deteriorate significantly due to various external reasons. In this work, we reveal that the domain structure and the dielectric layer formed at the electrode interface contribute significantly to the polarization switching speed of 10 nm thick Hf Zr O (HZO) film. The mechanism of speed degradation is related to the generation of charged defects in the film which accompany the formation of the interfacial dielectric layer during oxidization of the electrode. Such defects are pinning centers that prevent domain propagation upon polarization switching. To clarify this issue, we fabricate two types of similar W/HZO/TiN capacitor structures, differing only in the thickness of the electrode interlayer, and compare their ferroelectric (including local ferroelectric), dielectric, structural (including microstructural), chemical, and morphological properties, which are comprehensively investigated using several advanced techniques, in particular, hard X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electron beam induced current technique.

Radio systems for long‐range navigation comprise a subclass of radio‐navigation systems based on geodetically referenced and synchronized chains of terrestrial transmitting stations that provide accurate navigation at distances far from those stations. In fact, their development was an attempt to solve the problem of how to minimize the number of terrestrial transmitting stations needed to encompass the global operational area. The chapter aims at representing the very low frequency (VLF) and low frequency (LF) long‐range navigation systems including their principles of operation, accuracy, coverage, budget of errors, interfering signals, signal processing techniques, and sensor architecture. These subjects are augmented by including various system modernization aspects and their integration with satellite RNS. The Integrated Solution utilizes both GNSS and all‐Loran data to estimate additional secondary factor (ASF) corrections. The chapter provides all Loran‐only and GNSS‐only solutions to show how the GNSS or all Loran data contributes to the combined solutions.

Background. Studies of comorbid (syntropic) and inversely comorbid (rarely occurring together, i.e., dystropic) diseases have focused on the search for molecular causes of this phenomenon. Materials. We investigated DNA methylation levels in regulatory regions of 23 apoptosis-associated genes as candidate loci associated with the “cancer–neurodegeneration” dystropy in patients with Huntington’s disease (HD) and patients with non–small cell lung cancer (LC). Results. Statistically significant differences in methylation levels between the HD and LC groups were found for 41 CpG sites in 16 genes. The results show that five genes (SETDB1, TWIST1, HDAC1, SP1, and GRIA2) are probably involved in the phenomenon of inverse comorbidity of these diseases. For these genes, the methylation levels of the studied CpG sites were altered in opposite directions in the two groups of patients, compared to the control group. Conclusions. For the SP1 gene, the above hypothesis is supported by our analysis of open-access data on gene expression in patients with the aforementioned diagnoses and fits a probable mechanism of the “HD–LC” dystropy.

A mesoporous silica support was synthesized using the sol–gel method from trichlorosilane. There is a tendency for the specific surface area and the proportion of silica particles mesopores to increase during all stages of sol–gel synthesis. It has been shown that the insertion of hexane and toluene, as additional solvents, into the structure-forming polyethylene glycol, makes it possible to regulate the pore size and specific surface area of silica. Silica functionalization was carried out using SILP technology. The activities of the catalytic systems based on polymer and inorganic supports immobilized by imidazole-based ionic liquids during the trichlorosilane disproportionation reaction were compared. There is a tendency for the monosilane yield for catalytic systems based on an inorganic support to increase. We identified the most promising catalyst in terms of monosilane yield and proposed a bifunctional catalyst that exhibited activity in two parallel reactions: trichlorosilane disproportionation and silicon tetrachloride hydrogenation.

This work explored the zinc nanoparticles obtained by the one-stage induction flow levitation method. A 10 kW tube generator with an operating frequency of 440 kHz was used. The process used 8 mm diameter zinc granules (2 g weight) with a purity of 99.9%. Zinc wire was fed to replace the evaporated metal from the granule surface. This method productivity was 30 g/h of nanoparticles. In addition, various methods were used to characterize the resulting nanoparticles: scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-Ray fluorescence analysis (XRF), dynamic light scattering (DLS), porosimetry and inductively coupled plasma atomic emission spectroscopy (ICP-MS). The resulting nanoparticle size, determined by SEM and porosimetry, was 350 nm, while the size of the primary crystallites was 21 nm. The amount of impurities in the resulting nanoparticles did not exceed 1000 ppm.

AbstractPurposeComparative analysis of multilocus imprinting disturbances (MLIDs) in miscarriages from women with sporadic (SPL) and recurrent pregnancy loss (RPL) and identification of variants in the imprinting control gene NLRP7 that may lead to MLIDs.MethodsChorionic cytotrophoblast and extraembryonic mesoderm samples from first-trimester miscarriages were evaluated in 120 women with RPL and 134 women with SPL; 100 induced abortions were analyzed as a control group. All miscarriages had a normal karyotype. Epimutations in 7 imprinted genes were detected using methyl-specific PCR and confirmed with DNA pyrosequencing. Sequencing of all 13 exons and adjusted intron regions of the NLRP7 gene was performed.ResultsEpimutations in imprinted genes were more frequently detected (p < 0.01) in the placental tissues of miscarriages from women with RPL (7.1%) than in those of women with SPL (2.7%). The predominant epimutation was postzygotic hypomethylation of maternal alleles of imprinted genes (RPL, 5.0%; SPL, 2.1%; p < 0.01). The frequency of MLID was higher among miscarriages from women with RPL than among miscarriages from women with SPL (1.7% and 0.4%, respectively, p < 0.01). Variants in NLRP7 were detected only in miscarriages from women with RPL. An analysis of the parental origin of NLRP7 variants revealed heterozygous carriers in families with RPL who exhibited spontaneous abortions with MLIDs and compound heterozygosity for NLRP7 variants.ConclusionRPL is associated with NLRP7 variants that lead to germinal and postzygotic MLIDs that are incompatible with normal embryo development.Trial registration: Not applicable.