scholarly journals Thermal Stability and Radiation Tolerance of Lanthanide-Doped Cerium Oxide Nanocubes

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1369
Author(s):  
Kory Burns ◽  
Paris C. Reuel ◽  
Fernando Guerrero ◽  
Eric Lang ◽  
Ping Lu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
Radiation Stability ◽  
Ex Situ ◽  
In Situ Tem ◽  
Free Standing ◽  
X Ray ◽  
High Fluences ◽  
The Impact

The thermal and radiation stability of free-standing ceramic nanoparticles that are under consideration as potential fillers for the improved thermal and radiation stability of polymeric matrices were investigated by a set of transmission electron microscopy (TEM) studies. A series of lanthanide-doped ceria (Ln:CeOx; Ln = Nd, Er, Eu, Lu) nanocubes/nanoparticles was characterized as synthesized prior to inclusion into the polymers. The Ln:CeOx were synthesized from different solution precipitation (oleylamine (ON), hexamethylenetetramine (HMTA) and solvothermal (t-butylamine (TBA)) routes. The dopants were selected to explore the impact that the cation has on the final properties of the resultant nanoparticles. The baseline CeOx and the subsequent Ln:CeOx particles were isolated as: (i) ON-Ce (not applicable), Nd (34.2 nm), Er (27.8 nm), Eu (42.4 nm), and Lu (287.4 nm); (ii) HMTA-Ce (5.8 nm), Nd (6.6 nm), Er (370.0 nm), Eu (340.6 nm), and Lu (287.4 nm); and (iii) TBA-Ce (4.1 nm), Nd (5.0 nm), Er (3.8 nm), Eu (7.3 nm), and Lu (3.8 nm). The resulting Ln:CeOx nanomaterials were characterized using a variety of analytical tools, including: X-ray fluorescence (XRF), powder X-ray diffraction (pXRD), TEM with selected area electron diffraction (SAED), and energy dispersive X-ray spectroscopy (EDS) for nanoscale elemental mapping. From these samples, the Eu:CeOx (ON, HMTA, and TBA) series were selected for stability studies due to the uniformity of the nanocubes. Through the focus on the nanoparticle properties, the thermal and radiation stability of these nanocubes were determined through in situ TEM heating and ex situ TEM irradiation. These results were coupled with data analysis to calculate the changes in size and aerial density. The particles were generally found to exhibit strong thermal stability but underwent amorphization as a result of heavy ion irradiation at high fluences.

Direct Observation of Single Displacement Cascade in Pyrochlore by Tv-Rate In-Situ TEM and Ex-Situ HRTEM

2001 ◽  
Vol 7 (S2) ◽  
pp. 408-409
Author(s):  
J. Lian ◽  
L. M. Wang ◽  
S. X. Wang ◽  
R. C. Ewing
Keyword(s):  
Ion Irradiation ◽  
Heavy Ion ◽  
Ex Situ ◽  
In Situ Tem ◽  
Direct Impact ◽  
Displacement Cascade ◽  
Amorphous Domain ◽  
Rapid Kinetics ◽  
Kinetics Of

The ion irradiation-induced crystalline-to-amorphous transformation has been studied in many complex ceramics. Direct impact amorphization has been considered to be one of the fundamental amorphization mechanisms for complex ceramics under heavy ion irradiation . Based on the directimpact model, a highly energetic incident ion transfers its kinetic energy to the target as a thermal spike within 10“13 sec creating a “molten-like” displacement cascade, typically nanometer-scaled in diameter (as indicated by the result of a computer simulation in Fig. 1). This “molten” zone quickly quenches to a small amorphous domain within a few pico-seconds. Epitaxial recrystallization occurs around the amorphous/crystalline interface, so that the size of amorphous domains decrease with time. The accumulation and overlap of small amorphous domains eventually leads to complete amorphization of the irradiated material. Although the in-situTEM technique with the setup shown in Fig. 2 has been extensively applied to the study of the amorphization process in complex ceramics, most of the previous studies relied on in-situobservation of the electron diffraction pattern, and there has been a lack of solid evidence of direct impact amorphization due to the small nature of the cascades and the rapid kinetics of its evolution.

scholarly journals The impact of fluence dependent 120 MeV Ag swift heavy ion irradiation on the changes in structural, electronic, and optical properties of AgInSe2 nano-crystalline thin films for optoelectronic applications

RSC Advances ◽  
2021 ◽  
Vol 11 (42) ◽  
pp. 26218-26227
Author(s):  
R. Panda ◽  
S. A. Khan ◽  
U. P. Singh ◽  
R. Naik ◽  
N. C. Mishra
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
Swift Heavy Ion Irradiation ◽  
Heavy Ion Irradiation ◽  
Swift Heavy Ion ◽  
Nano Crystalline ◽  
Shi Irradiation ◽  
The Impact

Swift heavy ion (SHI) irradiation in thin films significantly modifies the structure and related properties in a controlled manner.

scholarly journals Structural Changes in French VF Treatment Wetland Porous Media during the Rest Period: An Ex Situ Study Using X-ray Tomography

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 389
Author(s):  
German Dario Martinez-Carvajal ◽  
Laurent Oxarango ◽  
Jérôme Adrien ◽  
Pascal Molle ◽  
Nicolas Forquet
Keyword(s):  
Porous Media ◽  
Structural Changes ◽  
Rest Period ◽  
Treatment Wetlands ◽  
Ex Situ ◽  
Initial Value ◽  
Treatment Wetland ◽  
X Ray ◽  
The Impact ◽  
Deposit Layer

Clogging constitutes a major operational issue for treatment wetlands. The rest period is a key feature of French Vertical Flow (VF) treatment wetlands and serves to mitigate clogging. An ex-situ drying experiment was performed to mimic the rest period and record structural changes in the porous media using X-ray Computed Tomography (CT). Samples containing the deposit and gravel layers of a first stage French VF treatment wetland were extracted and left to dry in a control environment. Based on CT scans, three phases were identified (voids, biosolids, and gravels). The impact of the rest period was assessed by means of different pore-scale variables. Ultimately, the volume of biosolids had reduced to 58% of its initial value, the deposit layer thickness dropped to 68% of its initial value, and the void/biosolid specific surface area ratio increased from a minimum value of 1.1 to a maximum of 4.2. Cracks greater than 3 mm developed at the uppermost part of the deposit layer, while, in the gravel layer, the rise in void volume corresponds to pores smaller than 2 mm in diameter. Lastly, the air-filled microporosity is estimated to have increased by 0.11 v/v.

Uranium–molybdenum nuclear fuel plates behaviour under heavy ion irradiation: An X-ray diffraction analysis

2009 ◽  
Vol 385 (2) ◽  
pp. 449-455 ◽  
Author(s):  
H. Palancher ◽  
N. Wieschalla ◽  
P. Martin ◽  
R. Tucoulou ◽  
C. Sabathier ◽  
...  
Keyword(s):  
Diffraction Analysis ◽  
Nuclear Fuel ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heavy Ion Irradiation

Study on Effects of Heavy Ion Irradiation on CeO2 by Using Synchrotron Radiation X-Ray Absorption Spectroscopy -as a Simulation Study for Radiation Damage in High-Burnup Light Water Reactor Fuels-

2007 ◽  
Vol 1043 ◽  
Author(s):  
Hirotaka Ohno ◽  
Daiju Matsumura ◽  
Yasuo Nishihata ◽  
Jun'ichiro Mizuki ◽  
Norito Ishikawa ◽  
...  
Keyword(s):  
Thin Films ◽  
Synchrotron Radiation ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
Waller Factor ◽  
X Ray ◽  
Debye Waller Factor ◽  
Atomic Distance ◽  
Exafs Measurement ◽  
X Ray Absorption

AbstractCeO2 thin films were irradiated with 200MeV Xe ions. Effects of the irradiation were studied by using Extended X-ray Absorption Fine Structure (EXAFS) measurement at SPring8 synchrotron radiation facility. EXAFS spectra for the irradiated thin films near the Ce K-edge show that the coordination number for oxygen atoms around Ce atom decreases and that the Ce-O Debye-Waller factor increases by the irradiation. The atomic distance between oxygen atom and Ce atom does not vary within the accuracy of EXAFS measurement. The effect of high density electronic excitation on the structure of CeO2 is discussed.

The Effect of Swift Heavy Ion Irradiation on Quasicrystals

2000 ◽  
Vol 643 ◽  
Author(s):  
Ratnamala Chatterjee ◽  
Aloke Kanjilal ◽  
A. Dunlop
Keyword(s):  
Ion Irradiation ◽  
Heavy Ion ◽  
Ex Situ ◽  
Stopping Power ◽  
Icosahedral Quasicrystal ◽  
Electronic Excitations ◽  
Nuclear Collisions ◽  
Heavy Ion Irradiation ◽  
Swift Heavy Ion ◽  
Ex Situ Xrd

AbstractThe effect of pure electronic excitations (by ∼ 835 MeV Kr irradiation) on a stable icosahedral quasicrystal is compared with the effect of electronic excitations combined with the nuclear collisions (by 100 MeV Ni irradiation) occurring in a similar quasicrystal. The critical stopping power was kept at 1300 eV/Å for both the experiments. Under the pure electronic excitations, the R(φ)/R(0) [ratio of resistance at fluence φ and the resistance on the same piece with zero fluence) of quasicrystal goes through oscillatory changes, until at ∼ 1 × 1012 ions/cm2where this ratio drops considerably. The ex-situ XRD on the irradiated sample does show the evidence of degradation of the structure. In contrast, the Ni- irradiated sample shows an increase in resistivity after a critical fluence of 2.5 × 1013 ions/cm2, which remains constant for higher fluences. Corresponding defect annihilation effects are observed in the XRD of Ni- irradiated samples.

scholarly journals In situ TEM study of G-phase precipitates under heavy ion irradiation in CF8 cast austenitic stainless steel

2015 ◽  
Vol 464 ◽  
pp. 185-192 ◽  
Author(s):  
Wei-Ying Chen ◽  
Meimei Li ◽  
Xuan Zhang ◽  
Marquis A. Kirk ◽  
Peter M. Baldo ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
In Situ Tem ◽  
Heavy Ion Irradiation

High-Resolution Spectrochemical Analysis of Columnar Defects Formed in Bi2Sr2CaCu2Ox by Swift Heavy Ion Irradiation

2003 ◽  
Vol 792 ◽  
Author(s):  
F. Kano ◽  
M. Terasawa ◽  
T. Mitamura ◽  
T. Kambara ◽  
Y. Sasaki ◽  
...  
Keyword(s):  
High Resolution ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
High Energy ◽  
Electron Gun ◽  
Spectrochemical Analysis ◽  
Columnar Defect ◽  
Defect Center ◽  
X Ray ◽  
Columnar Defects

ABSTRACTSingle-crystal specimen of high-temperature superconductor Bi2Sr2CaCu2Ox was irradiated with 3.5 GeV Xe ions at room temperature up to 1.0 × 1011 ion/cm2. Significant enhancement of magnetization by the irradiation was confirmed. The irradiated specimens were studied by using a high-resolution transmission electron microscope with field emission electron gun (FE-TEM), and, also, with an energy dispersive x-ray analyzer (EDS). Columnar defects with diameter of about 6 nm were observed along the incident ion tracks. By nanoscale high-resolution x-ray spectrochemical analysis across the columnar defect, enrichment of Cu and depletion of Bi, Sr and Ca in the columnar defect center, and vice versa in the outskirts of the defect, was found for the first time. Oxygen depletion in the defect, and increased distribution outside of the defect were also found by electron energy loss spectroscopy. This experimental evidence suggests that the columnar defects are formed as a consequence of Coulomb explosion induced by the electronic excitation of the high-energy heavy ions.

Epitaxial Layer Thickness Dependence on Heavy Ion Induced Charge Collection in 4H-SiC Schottky Barrier Diodes

2016 ◽  
Vol 858 ◽  
pp. 753-756
Author(s):  
Takahiro Makino ◽  
Shinobu Onoda ◽  
Norihiro Hoshino ◽  
Hidekazu Tsuchida ◽  
Takeshi Ohshima
Keyword(s):  
Schottky Barrier ◽  
Epitaxial Layer ◽  
Impact Ionization ◽  
Ion Irradiation ◽  
Single Species ◽  
Heavy Ion ◽  
Charge Collection ◽  
Lead Ion ◽  
Induced Charge ◽  
The Impact

The charge enhancement in SiC-Schottky Barrier Didoes (SBDs) with different epi-layer thicknesses under the condition of the single-species ion irradiation was simulated to find out the mechanism of heavy-ion-induced anomalous charge collection in SiC-SBDs. The value of ion induced charge depended on the thickness of epitaxial-layer in the SBDs. The simulation result suggests that the impact ionization is one of the key effects to lead ion induced charge enhancement.

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