RPL properties of samarium-doped CaSO4

Japanese Journal of Applied Physics

Published On 2022/2/2

Radiophotoluminescence (RPL) properties of Sm-doped CaSO 4 for radiation dosimetry applications are reported. The samples with varying Sm concentrations are prepared via the solid-state reaction process. The as-prepared samples show photoluminescence due to typical 4f–f transitions of Sm 3+ whereas, after X-ray irradiation, additional emission features appear with a broad band peaking at 630 nm as well as a set of multiple sharp lines across 680–820 nm, which are attributed to the 5d–4f and 4f–4f transitions of Sm 2+, respectively. Therefore, the RPL in the present material system relies on the generation of Sm 2+ centers. The sensitivity is about 3 times lower than that of Ag-doped phosphate glass, but no fading and build-up of signal are evident even immediately after the irradiation. The signal is reversible by heat-treatment at 500 C, and is reproducible even after the thermal erasure, especially when …

Journal

Japanese Journal of Applied Physics

Published On

2022/2/2

Volume

61

Page

SB1035

Authors

Safa Kasap

Safa Kasap

University of Saskatchewan

Position

Professor of Electrical Engineering

H-Index(all)

49

H-Index(since 2020)

29

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

electronic materials

optoelectronic and photonic materials

devices

detectors

photoconductors

University Profile Page

Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

Position

H-Index(all)

44

H-Index(since 2020)

19

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

Odor sensor

Dosimeter

Thin films

University Profile Page

Go Okada

Go Okada

Kanazawa Institute of Technology

Position

H-Index(all)

33

H-Index(since 2020)

28

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

Optoelectronics

Dosimetry

X-ray Imaging

Phosphor

University Profile Page

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Safa Kasap

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2023/12/20

Article Details
Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

Journal of Materials Science: Materials in Electronics

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Hidehito Nanto

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Kanazawa Institute of Technology

Materials Research Bulletin

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Japanese Journal of Applied Physics

Verification of effect of interference between multiple scatterers on the evaluation of backscattering coefficient

Backscatter coefficient analysis methods for biological tissues have been clinically applied but assume a homogeneous scattering medium. In addition, there are few examples of actual measurement studies in the HF band, and the consistency with theory has not been sufficiently confirmed. In this paper, the effect of correlations among scatterer positions on backscattering was investigated by performing experiments on inhomogeneous media having two types of scattering source with different structural and acoustic properties. In the echo data of phantoms containing two types of scatterer acquired by multiple sensors, the power and frequency dependence of the backscatter coefficient were different from theoretical calculations due to the interference effects of each scatterer. The effect of interference between the two types of scatterer was confirmed to be particularly strong for echoes acquired by the sensor at high …

Daisuke Yamane

Daisuke Yamane

Ritsumeikan University

Japanese Journal of Applied Physics

Multimode interference-based strain sensing using micro dry-etched perfluorinated polymer optical fibers

This study explores the impact of a micro dry-etching technique on strain sensing based on multimode interference in a perfluorinated polymer optical fiber (POF). We demonstrate a drastic shift in strain sensitivity, from+ 34 nm/% in a non-etched POF to− 981 nm/% in the etched POF. This notable change may be attributed to the excitation of the axially asymmetrical modes in the etched POF, which is confirmed through simulation on the stress distribution across the core. In addition, a critical wavelength for multimode interference is observed in a POF.

Emad M. Elsehly

Emad M. Elsehly

Damanhour University

Japanese Journal of Applied Physics

Crystal structure and thermoelectric properties of bulk polycrystalline (SbxBi1-x) 2Se3 alloys

Crystal structure and thermoelectric properties of several partially-substituted higher manganese silicides (HMSs) samples have been reviewed. HMSs possess a unique incommensurate crystal structure consisting of two subsystems of [Mn] and [Si] and the structure formula is thus represented as MnSi γ. The c-axis length ratio, γ, changes with temperature to yield the MnSi (monosilicide) striations, which deteriorate mechanical strength and electrical conductivity. A small amount of V-substitution effectively dissipates such striations and enhances hole carrier concentration. Thus prepared V-substituted samples exhibit the highest power factor and remarkably lower thermal conductivity. The nanostructure of such samples consists of regular and highly disordered nano-domains of Si atoms, which would further reduce the thermal conductivity to enhance thermoelectric figure-of-merit.

Tsuyoshi Hatano

Tsuyoshi Hatano

Nihon University

Japanese Journal of Applied Physics

Competitive coexistence of ferromagnetism and metal–insulatortransition of VO2 nanoparticles

We investigated the magnetic and electric properties of nanometer-sized vanadium dioxide (VO2) particles. VO2 nanoparticles were formed by milling VO2 powder. We measured the magnetic field dependence of the magnetization of the VO2 powder and nanoparticles. The VO2 powder did not exhibit ferromagnetism, whereas the VO2 nanoparticles exhibited ferromagnetism. In addition, we fabricated samples by bridging between electrodes with the VO2 nanoparticles, and the temperature dependence of their resistance was measured. Metal-insulator transitions (MITs) were observed, and the temperature range where the MIT occurred was wider than that in a typical bulk VO2. The VO2 nanoparticles exhibited these properties of ferromagnetism and MIT possibly because of the surface and size effects of the VO2 nanoparticles. These results indicate the first observation of the competitive coexistence of …

Toru Akiyama

Toru Akiyama

Mie University

Japanese Journal of Applied Physics

First-principles study on barrier height of silicon emission from interface into oxide during silicon thermal oxidation

Employing the first-principles calculation, the detailed energy landscape of the path for the Si emission from the interface into the oxide is studied. It is found that the barrier height almost reproduces the experimental values, which indicates that the Si emission surely corresponds to the diffusion of SiO interstitial. It is also found that the barrier height is microscopically rate-limited by the oxygen-vacancy transfer process, which temporarily and inevitably proceeds under a large local tensile strain induced by the diffusion of SiO interstitial.

Atsushi Ogura

Atsushi Ogura

Meiji University

Japanese Journal of Applied Physics

Local thermal conductivity properties of a SiGe nanowire observed by laser power sweep Raman spectroscopy

Using laser power sweep Raman spectroscopy, this research reports that the thermal transport changes with the wire width of silicon-germanium (SiGe) nanowires (NWs). The temperature in SiGe NWs was calculated using the relationship between Raman shift ω and temperature T (dω/dT) to evaluate the correlation between the thermal transport mechanism and SiGe NWs structure. We clarified that the thermal conductivity of the SiGe NWs decreases as the wire width becomes narrower. Also, a positional dependence of the thermal conductivity properties of the SiGe NWs was observed by laser power sweep Raman spectroscopy.

Taeho Kim

Taeho Kim

KAIST

Japanese Journal of Applied Physics

Novel strategies for low-voltage NAND flash memory with negative capacitance effect

Here, we present a novel approach to employing a negative capacitance (NC) phenomenon in the blocking oxide of CTF memory. To achieve this, we developed an inversible mono-domain ferroelectric (IMFE) film through high-pressure post-deposition annealing in a forming gas at 200 atm (FG-HPPDA). The FG-HPPDA process enables to form a uniform alignment of domains and facilitates invertible domain switching behavior in ferroelectrics, generating an internal field by the flexo-electric effect as well as interface-pinned polarization by chemical reaction. Subsequently, to stabilize the NC effect, we fabricated the IMFE/Al2O3 heterostructure, which exhibits an outstanding capacitance-boosting feature. Finally, we successfully demonstrate unprecedented CTF memory with the NC effect in a blocking oxide. Our unique CTF device shows the improved performance (maximum incremental-step-pulse-programming …

Hiroshi Kanai

Hiroshi Kanai

Tohoku University

Japanese Journal of Applied Physics

Automated mode chart generation for finite element analysis of piezoelectric resonators using principal component analysis based on clustering

This paper presents a new clustering method for identifying the vibration mode shapes of piezoelectric resonators using image processing and principal component analysis (PCA). The finite element method (FEM) is an indispensable tool for analyzing the vibration-displacement distribution of resonators and suppressing spurious vibration modes. Although the FEM exports eigenfrequencies as a list, including spurious vibration modes, recognizing the vibration shape of each eigenfrequency requires manual operation by operators to view the displacement distribution and identify the vibration shapes. The proposed method consists of a preprocessing step based on a threshold selection before the PCA step. Preprocessing significantly simplifies the vibration displacement distribution and reduces the amount of data required for post-processing PCA. The mode chart of the AT-cut quartz crystal resonator obtained …