Investigation of radiation defects in steatite ceramics SK-1 and SNC by the EPR method

2021 ◽  
Vol 23 (1) ◽  
pp. 42-46
Author(s):  
K.Kh. Saidakhmedov ◽  
I. Nuritdinov ◽  
M.I. Baydjanov
Keyword(s):  
Glass Phase ◽  
Epr Spectra ◽  
Structural Defects ◽  
Radiation Defects ◽  
Γ Irradiation ◽  
Paramagnetic Defect ◽  
Amorphous Phases ◽  
Epr Method ◽  
Defect Centers ◽  
High Doses

The EPR spectra of γ- and n-γ-reactor irradiated steatite ceramics SK-1 and SNC has been studied. It is shown that structural defects of the E ′-center type are created in the structure of the SK-1 and SNC ceramics under the action of high doses of γ-irradiation. After n-γ-irradiation and additional annealing, paramagnetic defect centers such as interstitial Me2++e− ions are created in the structure of the SNC ceramics, which are caused by amorphization of the ceramic crystal phase and the creation of a Mg enriched glass phase at the interface between crystalline and amorphous phases.

THE EPR STUDIES OF HIGH-Tc SUPERCONDUCTORS (Bi, Pb)-Ca-Sr-Cu-O

1991 ◽  
Vol 05 (10) ◽  
pp. 701-705 ◽  
Author(s):  
N. GUSKOS ◽  
S.K. PATAPIS ◽  
C. POLITIS
Keyword(s):  
Skin Effect ◽  
Epr Spectra ◽  
High Tc Superconductors ◽  
High Tc ◽  
Epr Method

The high-T c superconductors Bi 1.55 Pb 0.25 Sr 2 Ca 2.2 Cu 3 O 10, Bi 1.75 Pb 0.25 Sr 2 Ca 2 Cu 3 O 10 and Bi 1.75 Pb 0.25 Sr 2 Ca 3 Cu 4 O 12 (with about T c =106, 103 and 101 K, respectively) have been investigated using EPR method. Differences in intensities of the EPR spectra of Cu 2+ ions have been observed. These differences could be caused by the skin effect.

Point Defects in 4H-SiC Epilayers Introduced by 4.5 MeV Electron Irradiation and their Effect on Power JBS SiC Diode Characteristics

2013 ◽  
Vol 205-206 ◽  
pp. 451-456 ◽  
Author(s):  
Pavel Hazdra ◽  
Vít Záhlava ◽  
Jan Vobecký
Keyword(s):  
Electron Irradiation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Radiation Defects ◽  
Electrical Parameters ◽  
Power Diodes ◽  
Defect Centers ◽  
Measurement Results ◽  
Transient Spectroscopy ◽  
State Resistance

Electronic properties of radiation damage produced in 4H-SiC by electron irradiation and its effect on electrical parameters of Junction Barrier Schottky (JBS) diodes were investigated. 4H‑SiC N‑epilayers, which formed the low‑doped N-base of JBS power diodes, were irradiated with 4.5 MeV electrons with fluences ranging from 1.5x1014 to 5x1015 cm-2. Radiation defects were then characterized by capacitance deep-level transient spectroscopy and C-V measurement. Results show that electron irradiation introduces two defect centers giving rise to acceptor levels at EC‑0.39 and EC‑0.60 eV. Introduction rate of these centers is 0.24 and 0.65 cm‑1, respectively. These radiation defects have a negligible effect on blocking and dynamic characteristics of irradiated diodes, however, the acceptor character of introduced deep levels and their high introduction rates deteriorate diode’s ON-state resistance already at fluences higher than 1x1015 cm‑2.

scholarly journals Paramagnetic defect centers in BESOI and SIMOX buried oxides

1993 ◽  
Vol 40 (6) ◽  
pp. 1755-1764 ◽  
Author(s):  
W.L. Warren ◽  
M.R. Shaneyfelt ◽  
J.R. Schwank ◽  
D.M. Fleetwood ◽  
P.S. Winokur ◽  
...  
Keyword(s):  
Paramagnetic Defect ◽  
Defect Centers

Radiation Defects in Lime Mortars and Plasters Studied by EPR Spectroscopy

Radiocarbon ◽  
2020 ◽  
Vol 62 (3) ◽  
pp. 713-724
Author(s):  
Zuzanna Kabacińska ◽  
Danuta Michalska ◽  
Bernadeta Dobosz
Keyword(s):  
Epr Spectroscopy ◽  
Organic Radical ◽  
Radiation Defects ◽  
Paramagnetic Centers ◽  
Γ Irradiation ◽  
Paramagnetic Resonance ◽  
Crystalline Materials ◽  
Lime Mortars ◽  
Radiation Induced ◽  
Artificial Uv

ABSTRACTElectron paramagnetic resonance (EPR) spectroscopy is a well-established method of dating based on trapped charges, applied to various crystalline materials, including carbonates, bones, and teeth. It provides a detailed insight into the structure of radiation defects—paramagnetic centers generated by irradiation, without the need of a painstaking sample preparation, often challenging in other methods. Using EPR we studied the effect of γ radiation on lime mortars and plasters from ancient settlement Hippos in Israel, in order to analyze the process of defect generation. Analysis of the complex spectra revealed the presence of radiation-induced species, including CO2–, NO32– and organic radical. Using an artificial UV source, we generated relatively strong signals of paramagnetic centers, analogous to those created by γ irradiation, reaching their maximum intensity after 5–6 hr of UV exposure. Our results confirm the previous reports that radiation defects can also be generated, instead of bleached, in calcite by UV radiation, which is crucial for identifying the issues related to light exposition, affecting the accuracy of age determinations in trapped-charge dating methods.

Imaging of paramagnetic defect centers in solids

1986 ◽  
Vol 67 (2) ◽  
pp. 177-188 ◽  
Author(s):  
W Zommerfelds ◽  
M.J.R Hoch
Keyword(s):  
Paramagnetic Defect ◽  
Defect Centers

The Structure of SiO2-Sol-Gel Glasses Produced from Gels with Various Mole-Water per Mole-TEOS Ratios

1985 ◽  
Vol 61 ◽  
Author(s):  
George Kordas
Keyword(s):  
Gamma Ray ◽  
Sol Gel ◽  
Heat Treating ◽  
Paramagnetic Centers ◽  
Paramagnetic Defect ◽  
Defect Centers ◽  
Gamma Ray Irradiation ◽  
Gel Glasses

ABSTRACTSiO2-gels produced with 4,8, and 16 mol water per mol TEOS were densified up to 1000°C and then exposed to gamma-ray irradiation in order to produce paramagnetic defect centers. Various paramagnetic states were detected during densification of these gels, the formation of which depends on the mol water per mol TEOS ratio. In the gels O−2 ions were detected. The paramagnetic centers detected in the n = 16 gel with TH = 900°C were attributed to a non-bridging oxygen and an E'1-center. Three different O−2 ions, probably in interstitial positions, were detected in the n = 16-gel with TH = 1000°C. The CO−2 center was observed in the n = 8 gel with TH = 900°C. A variety of new components occur at TH = 1000°C in the n = 8 gel, the origin of which remains unresolved at present. The CH3, CO−2, and E1′-centers were detected in the n = 4 gel with TH = 700°C. The CO−2 and E′1 centers were preserved after heat treating the n = 4 gel at TH = 1000°C.

Investigation of structural defects in the crystals of synthetic mica (fluorophlogopite and taeniolite) by the EPR method

1972 ◽  
Vol 12 (4) ◽  
pp. 562-566
Author(s):  
A. I. Novozhilov ◽  
M. I. Samoilovich ◽  
I. N. Anikin ◽  
A. A. Sergeev-Bobr
Keyword(s):  
Structural Defects ◽  
Epr Method ◽  
Synthetic Mica
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