Study of material uniformity in high-resistivity Cd1−xZnxTe and Cd1−xMnxTe crystals

Background: Solid Lipid Nanoparticles (SLNs) possess unique in vivo features such as high resistivity, bioavailability, and habitation at the target site. Coating nanoparticles with polymers such as chitosan greatly affects their pharmacokinetic behavior, stability, tissue uptake, and controlled drug delivery. The aim of this study was to prepare and evaluate the biodistribution of 99mTc-labeled SLNs and chitosan modified SLNs in mice. Methods: 99mTc-oxine was prepared and utilized to radiolabel pre-papered SLNs or chitosan coated SLNs. After purification of radiolabeled SLNs (99mTc-SLNs) and radiolabeled chitosan-coated SLNs (99mTc-Chi-SLNs) using Amicon filter, they were injected into BALB/c mice to evaluate their biodistribution patterns. In addition, nanoparticles were characterized using Transmission Electron Microscopy (TEM), Fourier-transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-ray Powder Diffraction (XRD) and Dynamic Light Scattering (DLS). Results: 99mTc-oxine with high radiochemical purity (RCP~100%) and stability (RCP > 97% at 24 h) was used to provide 99mTc-SLNs and 99mTc-Chi-SLNs with high initial RCP (100%). TEM image and DLS data suggest 99mTc- SLNs susceptibility to aggregation. To that end, the main portion of 99mTc-SLNs radioactivity accumulates in the liver and intestines, while 99mTc-Chi-SLNs sequesters in the liver, intestines and kidneys. The blood radioactivity of 99mTc-Chi-SLNs was higher than that of 99mTc-SLNs by 7.5, 3.17 and 3.5 folds at 1, 4 and 8 h post-injection. 99mTc- Chi-SLNs uptake in the kidneys in comparison with 99mTc-SLNs was higher by 37.48, 5.84 and 11 folds at 1, 4 and 8h. Conclusion: The chitosan layer on the surface of 99mTc-Chi-SLNs reduces lipophilicity in comparison with 99mTc- SLNs. Therefore, 99mTc-Chi-SLNs are less susceptible to aggregation, which leads to their lower liver uptake and higher kidney uptake and blood concentration.

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Growth of homogeneous high resistivity fz silicon crystals under magnetic filed bias

Journal of Crystal Growth ◽

10.1016/0022-0248(81)90045-2 ◽

1981 ◽

Vol 55 (2) ◽

pp. 406-408 ◽

Cited By ~ 15

Author(s):

N. De Leon ◽

J. Guldberg ◽

J. Salling

Keyword(s):

High Resistivity ◽

Silicon Crystals ◽

Magnetic Filed

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A RF Redundant TSV Interconnection for High Resistance Si Interposer

Micromachines ◽

10.3390/mi12020169 ◽

2021 ◽

Vol 12 (2) ◽

pp. 169

Author(s):

Mengcheng Wang ◽

Shenglin Ma ◽

Yufeng Jin ◽

Wei Wang ◽

Jing Chen ◽

...

Keyword(s):

Millimeter Wave ◽

High Frequency ◽

High Performance ◽

Rapid Development ◽

Coplanar Waveguide ◽

Equivalent Circuit Model ◽

High Resistivity ◽

Performance Requirements ◽

Wave Radar ◽

Interconnect Design

Through Silicon Via (TSV) technology is capable meeting effective, compact, high density, high integration, and high-performance requirements. In high-frequency applications, with the rapid development of 5G and millimeter-wave radar, the TSV interposer will become a competitive choice for radio frequency system-in-package (RF SIP) substrates. This paper presents a redundant TSV interconnect design for high resistivity Si interposers for millimeter-wave applications. To verify its feasibility, a set of test structures capable of working at millimeter waves are designed, which are composed of three pieces of CPW (coplanar waveguide) lines connected by single TSV, dual redundant TSV, and quad redundant TSV interconnects. First, HFSS software is used for modeling and simulation, then, a modified equivalent circuit model is established to analysis the effect of the redundant TSVs on the high-frequency transmission performance to solidify the HFSS based simulation. At the same time, a failure simulation was carried out and results prove that redundant TSV can still work normally at 44 GHz frequency when failure occurs. Using the developed TSV process, the sample is then fabricated and tested. Using L-2L de-embedding method to extract S-parameters of the TSV interconnection. The insertion loss of dual and quad redundant TSVs are 0.19 dB and 0.46 dB at 40 GHz, respectively.

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The Primary Origin of Excellent Dielectric Properties of (Co, Nb) Co-Doped TiO2 Ceramics: Electron-Pinned Defect Dipoles vs. Internal Barrier Layer Capacitor Effect

Molecules ◽

10.3390/molecules26113230 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3230

Author(s):

Theeranuch Nachaithong ◽

Narong Chanlek ◽

Pairot Moontragoon ◽

Prasit Thongbai

Keyword(s):

Dielectric Properties ◽

Loss Tangent ◽

Barrier Layer ◽

Dielectric Response ◽

High Resistivity ◽

Low Loss ◽

Rutile Tio2 ◽

Complex Defect ◽

Very High ◽

Co Doped

(Co, Nb) co-doped rutile TiO2 (CoNTO) nanoparticles with low dopant concentrations were prepared using a wet chemistry method. A pure rutile TiO2 phase with a dense microstructure and homogeneous dispersion of the dopants was obtained. By co-doping rutile TiO2 with 0.5 at.% (Co, Nb), a very high dielectric permittivity of ε′ » 36,105 and a low loss tangent of tanδ » 0.04 were achieved. The sample–electrode contact and resistive outer-surface layer (surface barrier layer capacitor) have a significant impact on the dielectric response in the CoNTO ceramics. The density functional theory calculation shows that the 2Co atoms are located near the oxygen vacancy, creating a triangle-shaped 2CoVoTi complex defect. On the other hand, the substitution of TiO2 with Nb atoms can form a diamond-shaped 2Nb2Ti complex defect. These two types of complex defects are far away from each other. Therefore, the electron-pinned defect dipoles cannot be considered the primary origins of the dielectric response in the CoNTO ceramics. Impedance spectroscopy shows that the CoNTO ceramics are electrically heterogeneous, comprised of insulating and semiconducting regions. Thus, the dielectric properties of the CoNTO ceramics are attributed to the interfacial polarization at the internal insulating layers with very high resistivity, giving rise to a low loss tangent.

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“Perfect” Terahertz Vortex Beams Formed Using Diffractive Axicons and Prospects for Excitation of Vortex Surface Plasmon Polaritons

Applied Sciences ◽

10.3390/app11020717 ◽

2021 ◽

Vol 11 (2) ◽

pp. 717

Author(s):

Boris Knyazev ◽

Valery Cherkassky ◽

Oleg Kameshkov

Keyword(s):

Surface Plasmon ◽

Surface Plasmon Polaritons ◽

Bessel Beam ◽

Diffraction Theory ◽

Terahertz Range ◽

High Resistivity ◽

Visible Range ◽

Optical Elements ◽

Scalar Diffraction ◽

Plasmon Polaritons

Transformation of a Bessel beam by a lens results in the formation of a “perfect” vortex beam (PVB) in the focal plane of the lens. The PVB has a single-ring cross-section and carries an orbital angular momentum (OAM) equal to the OAM of the “parent” beam. PVBs have numerous applications based on the assumption of their ideal ring-type structure. For instance, we proposed using terahertz PVBs to excite vortex surface plasmon polaritons propagating along cylindrical conductors and the creation of plasmon multiplex communication lines in the future (Comput. Opt. 2019, 43, 992). Recently, we demonstrated the formation of PVBs in the terahertz range using a Bessel beam produced using a spiral binary silicon axicon (Phys. Rev. A 2017, 96, 023846). It was shown that, in that case, the PVB was not annular, but was split into nested spiral segments, which was obviously a consequence of the method of Bessel beam generation. The search for methods of producing perfect beams with characteristics approaching theoretically possible ones is a topical task. Since for the terahertz range, there are no devices like spatial modulators of light in the visible range, the main method for controlling the mode composition of beams is the use of diffractive optical elements. In this work, we investigated the characteristics of perfect beams, the parent beams being quasi-Bessel beams created by three types of diffractive phase axicons made of high-resistivity silicon: binary, kinoform, and “holographic”. The amplitude-phase distributions of the field in real perfect beams were calculated numerically in the approximation of the scalar diffraction theory. An analytical expression was obtained for the case of the binary axicon. It was shown that a distribution closest to an ideal vortex was obtained using a holographic axicon. The resulting distributions were compared with experimental and theoretical distributions of the evanescent field of a plasmon near the gold–zinc sulfide–air surface at different thicknesses of the dielectric layer, and recommendations for experiments were given.

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Tuning the Electrical Properties of NiO Thin Films by Stoichiometry and Microstructure

Coatings ◽

10.3390/coatings11060697 ◽

2021 ◽

Vol 11 (6) ◽

pp. 697

Author(s):

Yu-He Liu ◽

Xiao-Yan Liu ◽

Hui Sun ◽

Bo Dai ◽

Peng Zhang ◽

...

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Energy Loss ◽

Single Crystal ◽

Oxygen Stoichiometry ◽

High Resistivity ◽

Edge Structure ◽

Glass Substrates ◽

Lower Resistivity

Here, the electrical properties of NiO thin films grown on glass and Al2O3 (0001) substrates have been investigated. It was found that the resistivity of NiO thin films strongly depends on oxygen stoichiometry. Nearly perfect stoichiometry yields extremely high resistivity. In contrast, off-stoichiometric thin films possess much lower resistivity, especially for oxygen-rich composition. A side-by-side comparison of energy loss near the edge structure spectra of Ni L3 edges between our NiO thin films and other theoretical spectra rules out the existence of Ni3+ in NiO thin films, which contradicts the traditional hypothesis. In addition, epitaxial NiO thin films grown on Al2O3 (0001) single crystal substrates exhibit much higher resistivity than those on glass substrates, even if they are deposited simultaneously. This feature indicates the microstructure dependence of electrical properties.

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Ultrafast, broadband and tunable THz reflector based on high resistivity silicon

2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) ◽

10.1109/irmmw-thz46771.2020.9370950 ◽

2020 ◽

Author(s):

S. Kumar ◽

A. Nivedan ◽

A. Singh ◽

M. Tondusson ◽

J. Degert ◽

...

Keyword(s):

High Resistivity ◽

High Resistivity Silicon

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Studying the Depth Structure of the Kyrgyz Tien Shan by Using the Seismic Tomography and Magnetotelluric Sounding Methods

Geosciences ◽

10.3390/geosciences11030122 ◽

2021 ◽

Vol 11 (3) ◽

pp. 122

Author(s):

Irina Medved ◽

Elena Bataleva ◽

Michael Buslov

Keyword(s):

Seismic Tomography ◽

High Velocity ◽

Fault Zones ◽

Magnetotelluric Sounding ◽

Tien Shan ◽

High Resistivity ◽

Low Velocity ◽

Low Resistivity ◽

Velocity Models ◽

Fluid Saturation

This paper presents new results of detailed seismic tomography (ST) on the deep structure beneath the Middle Tien Shan to a depth of 60 km. For a better understanding of the detected heterogeneities, the obtained velocity models were compared with the results of magnetotelluric sounding (MTS) along the Kekemeren and Naryn profiles, running parallel to the 74 and 76 meridians, respectively. We found that in the study region the velocity characteristics and geoelectric properties correlate with each other. The high-velocity high-resistivity anomalies correspond to the parts of the Tarim and Kazakhstan-Junggar plates submerged under the Tien Shan. We revealed that the structure of the Middle Tien Shan crust is conditioned by the presence of the Central Tien Shan microcontinent. It manifests itself as two anomalies lying one below the other: the lower low-velocity low-resistivity anomaly, and the upper high-velocity high-resistivity anomaly. The fault zones, limiting the Central Tien Shan microcontinent, appear as low-velocity low-resistivity anomalies. The obtained features indicate the fluid saturation of the fault zones. According to the revealed features of the Central Tien Shan geological structure, it is assumed that the lower-crustal low-velocity layer can play a significant role in the delamination of the mantle part of the submerged plates.

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