Radiation-induced reduction of Eu3+ doped in SrAl2O4

Materials Letters

Published On 2021/11/15

In this letter, we report radio-photoluminescence (RPL) properties of Eu-doped SrAl2O4. The RPL is a phenomenon in which a new luminescence center is generated by ionizing radiation. The material was synthesized via the solid-state reaction. The synthesized sample shows photoluminescence (PL) due to the 4f-4f transition of Eu3+ and the 4f65d1 → 4f7 transition of Eu2+. After X-ray irradiation, the former emission intensity decreases while the latter one increases, and the extent of the change depends on the radiation dose. The change in the RPL is attributed to a reduction of Eu3+ by trapping an X-ray generated electron (Eu3+→Eu2+). In addition, a heat-treatment effectively reverses the above reaction by detrapping an electron from the Eu2+ center.

Journal

Materials Letters

Published On

2021/11/15

Volume

303

Page

130502

Authors

Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

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44

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19

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0

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Odor sensor

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Article Details
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Article Details
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Materials Letters

Texture study of Ti64xCryNi alloys developed by μ-plasma additive manufacturing process

This manuscript presents study of crystallographic texture, phase maps, fraction of β-Ti and α-Ti phases, grain size of α-Ti phase of the Ti64xCryNi alloys developed by μ-plasma additive manufacturing process by adding Cr and/or Ni to aerospace grade Ti64 alloy. Results reveal that addition of Cr and/or Ni refined grains of α-Ti phase and enhanced fraction of β-Ti phase in the developed Ti64xCryNi alloys. Analysis crystallographic texture and phase maps found that grains of the β-Ti and α-Ti phases in the developed alloys are oriented in different directions thus reducing their texture intensity which weakens their texture. It reduced anisotropy thus making mechanical properties uniform in the loading directions. Such texture will be beneficial for those applications where uniform properties are required such as the components subjected to the multi-directional loads in aerospace and automobile applications.

Ayan Bhowmik

Ayan Bhowmik

Nanyang Technological University

Materials Letters

A Machine learning perspective on hardness prediction in advanced multicomponent Al-Mg based lightweight alloys

Achieving the desired hardness in Al-Mg alloys through experimentation is challenging, costly, and time-consuming, given the extensive composition variations and diverse aging conditions. This research utilizes a range of machine learning (ML) techniques to expedite the advancement of high-performance Al-Mg alloys. The research focused on Al-Mg-X (where X represents elements like Cu, Zn, etc.) alloys, compiling data from literature sources that included composition of alloy, the conditions under which aging occurred (including both time and temperature factors), various physical properties, and the measurement of hardness. These datasets were employed to train seven different ML algorithms aimed at predicting Al alloys with enhanced hardnesses. The findings indicated that the CatBoost model proved effective in forecasting the hardness with excellent predictive performance, surpassing other machine …

MUHAMMAD FAISAL KHYASUDEEN

MUHAMMAD FAISAL KHYASUDEEN

Universiti Malaya

Materials Letters

Kretschmann-based plasmonic excitation of 2D organic semiconductor at visible wavelengths

We studied the Kretschmann-based surface plasmon resonance (K-SPR) of two-dimensional organic semiconductor materials, namely manganese (III) phthalocyanine chloride (MnPcCl) and vanadyl-2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO). The K-SPR measurements indicate that VOPcPhO exhibits superior performance compared to MnPcCl, as evidenced by the stronger absorption and narrower SPR peaks. Oxygen-vanadium coupling in the central metal atom facilitates high absorption, potentially enabling strong plasmon-exciton coupling, which can be harnessed for efficient photovoltaic and optical memory devices.

Martina Scapin

Martina Scapin

Politecnico di Torino

Materials Letters

Dynamic behavior of porous graphite under laser-induced shocks

The present study focuses on developing reliable numerical models to describe the mechanical behavior of isotropic polycrystalline graphite subjected to laser shocks. Isotropic graphite of nuclear grade, which was extensively used in Beam Intercepting Devices of particle accelerators, is characterized by a high porosity enabling effective absorption of laser-induced shockwaves. Accurate numerical models which aim at describing shockwaves traveling inside porous graphite must take into account the effect of pores on the structural response of the material. In this work the Fu Chang foam material model was calibrated to capture the behavior of R4550 graphite. Based on the foam material model, hydrodynamic simulations were developed and compared to experimental data from literature and from PHELIX experimental campaign.

George Youssef, Ph.D., P.E.

George Youssef, Ph.D., P.E.

San Diego State University

Materials Letters

Tunable and switchable magnetoresistance of P3HT: PCBM organic framework

This letter demonstrates a multifunctional electronic device based on an organic multiferroic fabricated with newly synthesized polythiophenes and fullerene derivative polymers with crystal sizes in the millimeter and micrometer scales, respectively. The novelty of the presented framework is the insensitivity to the fabrication process and physical demonstration of organic multiferroics. Devices with drastically different functionalities were fabricated using the same processing steps. We demonstrate a non-contact magnetic field sensor based on magneto-resistivity. Remarkably, the same device exemplifies a magnetic data storage characteristics.

Davood Rahmatabadi (ORCID:0000-0002-6898-3061)

Davood Rahmatabadi (ORCID:0000-0002-6898-3061)

University of Tehran

Materials Letters

3D printing super stretchable propylene-based elastomer

Stretchable elastomers play a crucial role in various applications such as soft robotics and flexible electronics. Traditional manufacturing methods for stretchable elastomers face limitations in terms of material waste and production time. This paper presents a direct pellet printing technique using pneumatic pressure to fabricate a highly stretchable propylene-based elastomer. By feeding polymer pellets into a customized pellet printer and regulating pneumatic pressure, the filament buckling issue is overcome, and precise material flow control is achieved, resulting in a uniform microstructure. Tensile testing reveals that the 3D printed elastomer exhibits exceptional elongation exceeding 4000%. Scanning electron microscopy confirms seamless interlayer bonding, contributing to the material's stretchability. This technique opens up new possibilities for soft stretchable devices.