Study of paramagnetic defect centers in as-grown and annealed TiO 2 anatase and rutile nanoparticles by a variable-temperature X-band and high-frequency (236 GHz) EPR

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.

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Conduction Currents and Paramagnetic Defect Centers in UV-Illuminated Silicon Nitride Films

ECS Meeting Abstracts ◽

10.1149/ma2011-02/27/1908 ◽

2011 ◽

Keyword(s):

Silicon Nitride ◽

Paramagnetic Defect ◽

Silicon Nitride Films ◽

Defect Centers

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Imaging of paramagnetic defect centers in solids

Journal of Magnetic Resonance (1969) ◽

10.1016/0022-2364(86)90426-9 ◽

1986 ◽

Vol 67 (2) ◽

pp. 177-188 ◽

Cited By ~ 1

Author(s):

W Zommerfelds ◽

M.J.R Hoch

Keyword(s):

Paramagnetic Defect ◽

Defect Centers

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High-frequency circuit simulation in X-band coupled-cavity TWT

2015 IEEE International Vacuum Electronics Conference (IVEC) ◽

10.1109/ivec.2015.7223987 ◽

2015 ◽

Author(s):

Peng Chao-Huang ◽

Hui-Xu ◽

Wei Ling-Qi ◽

Tian-Liang ◽

Da Xi-Ji

Keyword(s):

High Frequency ◽

Circuit Simulation ◽

X Band ◽

Coupled Cavity

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

MRS Proceedings ◽

10.1557/proc-61-419 ◽

1985 ◽

Vol 61 ◽

Cited By ~ 2

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.

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High-frequency characteristic investigation of X-band five-unit TTTO

The 30th International Conference on Plasma Science, 2003. ICOPS 2003. IEEE Conference Record - Abstracts. ◽

10.1109/plasma.2003.1228641 ◽

2003 ◽

Author(s):

Daibing Chen ◽

Hu He ◽

Qingxiang Liu

Keyword(s):

Frequency Characteristic ◽

High Frequency ◽

X Band

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Electrical performances of AlInN/GaN HEMTs. A comparison with AlGaN/GaN HEMTs with similar technological process

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078711000419 ◽

2011 ◽

Vol 3 (3) ◽

pp. 301-309 ◽

Cited By ~ 9

Author(s):

Olivier Jardel ◽

Guillaume Callet ◽

Jérémy Dufraisse ◽

Michele Piazza ◽

Nicolas Sarazin ◽

...

Keyword(s):

High Frequency ◽

Continuous Wave ◽

High Electron Mobility Transistors ◽

High Electron ◽

Power Added Efficiency ◽

Electron Mobility Transistors ◽

X Band ◽

Gan Hemts ◽

Load Pull ◽

Interesting Alternative

A study of the electrical performances of AlInN/GaN High Electron Mobility Transistors (HEMTs) on SiC substrates is presented in this paper. Four different wafers with different technological and epitaxial processes were characterized. Thanks to intensive characterizations as pulsed-IV, [S]-parameters, and load-pull measurements from S to Ku bands, it is demonstrated here that AlInN/GaN HEMTs show excellent power performances and constitute a particularly interesting alternative to AlGaN/GaN HEMTs, especially for high-frequency applications beyond the X band. The measured transistors with 250 nm gate lengths from different wafers delivered in continuous wave (cw): 10.8 W/mm with 60% associated power added efficiency (PAE) at 3,5 GHz, 6.6 W/mm with 39% associated PAE at 10.24 GHz, and 4.2 W/mm with 43% associated PAE at 18 GHz.

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