Degradation Mechanism of Secondary Electron Emission in Plasma-Exposed MgO Films

Yu, Hak Ki; Kim, Woong-Kwon; Lee, Jong‐Lam; Park, Eung Chul; Kim, Jae Sung; Ryu, Jae Hwa

doi:10.1143/jjap.48.076003

Cited by 6 publications

(4 citation statements)

References 14 publications

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“…For instance, when the deposition of atoms occurs at temperatures well above the Mg melting point (923 K), Mg vacancies can be stabilized in an excess of oxygen atmosphere (0.33 mbar). On the contrary, if the substrate temperature is held below 700 K, a pressure of about 5×10 −4 mbar is required to optimize the film quality, while the replacement of oxygen with heavier Ar + plasma ion, which increases the growth rate, significantly altered the Mg-to-O ratio [12,13]. This allows for a control on the final number of cation vacancies in films [8].…”

Section: Resultsmentioning

confidence: 99%

Blue luminescence at room temperature in defective MgO films

Martínez-Boubeta

Martínez

Hernández

et al. 2011

Solid State Communications

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Luminescence spectroscopy has been used to characterize MgO films prepared by rf-sputtering. A clear correlation is found between the appearance of an emission peak centered at approximately 460 nm and the detection of ferromagnetic ordering in the samples. We suggest that cationic vacancies are responsible for the blue-light emission by introducing p states into the electronic band-gap. In accordance with this, our results strongly indicate that cationic vacancies are at the heart of the appearance of long-range magnetic ordering in MgO films.

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Section: Resultsmentioning

confidence: 99%

Blue luminescence at room temperature in defective MgO films

Martínez-Boubeta

Martínez

Hernández

et al. 2011

Solid State Communications

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“…Such a vacancy concentration ϳ10 21 / cm 3 , although high, is not unusual in MgO. 24,41 For the sake of comparison, in virgin MgO crystals the concentration of V-type centers is typically ϳ10 18 / cm 3 . 42 It should be mentioned that in our case the deposition of atoms proceeded at temperatures well above the Mg melting point ͑ϳ923 K͒.…”

Section: A Structural Characterizationmentioning

confidence: 99%

Ferromagnetism in transparent thin films of MgO

et al. 2010

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We show both theoretical and experimental evidences of the appearance of ferromagnetism in MgO thin films. First-principles calculations allow predicting the possibility of the formation of a local moment in MgO, provided the existence of Mg vacancies which create holes on acceptor levels near the O 2p-dominated valence band. Magnetic measurements evidence of the existence of room-temperature ferromagnetism in MgO thin films. High-resolution transmission electron microscopy demonstrates the existence of cation vacancies in our samples. Finally, by applying the element specificity of the x-ray magnetic circular dichroism technique, we also demonstrate that the magnetic moments of the system arise from the spin polarization of the 2p electrons of oxygen atoms surrounding Mg vacancies.

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“…Measurement of secondary electron emission (SEE) coefficient (γ) was done using a breakdown voltage (V B ) measurement system from Paschen relation. 20,21 ' EXPERIMENTAL SECTION An n +2 -type (100) silicon substrate doped with arsenic (resistivity < 0.004 Ω 3 cm) was used as a starting substrate.…”

Section: ' Introductionmentioning

confidence: 99%

“…Moreover, the MgO films with high concentration of oxygen vacancies were examined for application to secondary electron emitter. Measurement of secondary electron emission (SEE) coefficient (γ) was done using a breakdown voltage ( V B ) measurement system from Paschen relation. , …”

Section: Introductionmentioning

confidence: 99%

Enhanced Secondary Electron Emission in Nanoscale Thin Metal Containing MgO Film: Laser Irradiation on Creation of F Centers

Kim

Park³

et al. 2011

J. Phys. Chem. C

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A number of oxygen vacancies were found in the MgO film when a nanoscale-metal embedded MgO film (MgO/nanoscale metal film/MgO) was exposed to a pulsed KrF excimer laser. This was due to the interfacial reaction between embedding nanoscale metal and MgO film. In a case of Nb embedding metal, the Nb 2 O 5 crystallites were evidenced to proceed the reaction at the MgO/Nb interface; 5MgO + 2Nb f Nb 2 O 5 + 5Mg + 5V O 3 3 . The oxygen vacancies formed the F centers in the MgO bandgap, resulting in high cathodoluminescence intensity at the 431 and 526 nm region, corresponding to F + and F centers. The F centers in MgO played a role in increasing secondary electron emission coefficient (γ). As several kinds of nanoscale metals for creating F centers (Cr, Ti, V, In, Ta, and Nb) were embedded into MgO film, the γ values were found to be inversely linear with the ΔG f for the formation of metal oxides. The Nb embedded MgO film showed the highest γ value of ∼0.232 compared with normal MgO film (0.034).

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Degradation Mechanism of Secondary Electron Emission in Plasma-Exposed MgO Films

Cited by 6 publications

References 14 publications

Blue luminescence at room temperature in defective MgO films

Blue luminescence at room temperature in defective MgO films

Ferromagnetism in transparent thin films of MgO

Enhanced Secondary Electron Emission in Nanoscale Thin Metal Containing MgO Film: Laser Irradiation on Creation of F Centers

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